JPS5934140A - Manufacture of material of gas-sensitive body - Google Patents
Manufacture of material of gas-sensitive bodyInfo
- Publication number
- JPS5934140A JPS5934140A JP57144512A JP14451282A JPS5934140A JP S5934140 A JPS5934140 A JP S5934140A JP 57144512 A JP57144512 A JP 57144512A JP 14451282 A JP14451282 A JP 14451282A JP S5934140 A JPS5934140 A JP S5934140A
- Authority
- JP
- Japan
- Prior art keywords
- gas
- life
- sensitive
- heating
- urea
- 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.)
- Granted
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/12—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a solid body in dependence upon absorption of a fluid; of a solid body in dependence upon reaction with a fluid, for detecting components in the fluid
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は可燃性ガスなどのガス検知素子に用いるガス感
応体材料の製造方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for producing a gas sensitive material used in a gas sensing element for detecting combustible gases and the like.
従来例の構成とその問題点
近年、ガス機器の普及に伴なって、ガス漏れによる事故
が多発し、これらの事故を防ぐ方法が種々検討されてい
る１、従来から使用されているガス検知素子の代表的な
ものの一つとして、ｎ型の金属酸化物半導体を用いたも
のが知られている。半導体式ガス検知素子は通常速い応
答速度を要求されるので、ガス感応体は大気中で高温度
に保持されて用いられる。そのため、ガス感応体として
は酸化雰囲気に対して安定な酸化物が選ばれる。Conventional structure and its problems In recent years, with the spread of gas appliances, accidents due to gas leaks have been occurring frequently, and various methods to prevent these accidents are being studied.1. Conventionally used gas detection elements As one of the typical examples, one using an n-type metal oxide semiconductor is known. Since semiconductor type gas sensing elements are usually required to have a fast response speed, the gas sensitive body is used while being maintained at a high temperature in the atmosphere. Therefore, an oxide that is stable against an oxidizing atmosphere is selected as the gas sensitive material.
これまで各種の酸化物がガス感応体として用いられてき
たが、最近、酸化第二鉄のうち、これまでガスにほとん
ど感じないとされていたコランダム型の結晶構造を有す
るアルファ型酸化第二鉄（α−Ｆｅ２０ｓ ）が優れた
感ガス特性を示し得ることが見い出され、これを感応体
としたガス検知素子の検Ｒ’］が進められている。Until now, various oxides have been used as gas sensitive materials, but recently alpha-type ferric oxide, which has a corundum-type crystal structure that was thought to be hardly sensitive to gases, has been used. It has been discovered that (α-Fe20s) can exhibit excellent gas-sensitive characteristics, and testing of gas sensing elements using this as a sensitive material is underway.
このα−Ｆｅ２０３を用いた場合のガス検知素子は素子
の温度が３６０〜４５０°Ｃの範囲においてガス感応特
性が顕著であり、感度（通常空気中での抵抗値Ｒａと検
知すべきガス濃度中での抵抗値Ｒｑとの比で表わされる
）、および検知すべき濃度範囲における単位ガス濃度光
たりの抵抗値の変化率が大きいので、検知すべきガス濃
度を定量度よく抵抗値変化として検知できるという優れ
た特徴を持っている〇
一般にこのようなガス検知素子においては、できるだけ
少ない電力で感応体を効率よく加熱する必要があるので
、感応体はおのずと小さいものになる。セラミック半導
体式の場合も同様である。The gas detection element using this α-Fe203 has remarkable gas sensitivity characteristics in the temperature range of 360 to 450°C, and the sensitivity (normal resistance value Ra in air and gas concentration to be detected) is (represented by the ratio to the resistance value Rq) and the rate of change in resistance value per unit gas concentration light in the concentration range to be detected is large, so the gas concentration to be detected can be detected as a change in resistance value with good quantification. In general, in such gas sensing elements, it is necessary to heat the sensitive body efficiently with as little electric power as possible, so the sensitive body naturally becomes small. The same applies to the ceramic semiconductor type.
したがって感応体が２種以上の成分で構成されたものに
ついては、その成分が感応体に均一に含凍れていないと
素子間のばらつきの原因となる１、また素子そのものが
外気に直接暴露され、過酷な条件下で使用されるため、
特に長期の課電寿命に対して不安定になシやすいので、
ガス感応体はできるだけ均質な微細構造を有している必
要がある。Therefore, if the sensitive material is composed of two or more types of components, if the components are not uniformly contained in the sensitive material, it may cause variations between devices1, and the device itself may be directly exposed to the outside air. , used under harsh conditions,
In particular, it tends to become unstable over a long period of energized life, so
The gas sensitive body must have a microstructure that is as homogeneous as possible.
このため、製造方法としては水溶液法（共沈法や均質沈
殿法等）が有力な方法となる。これによると分散混合が
優れているほかに、微粒子粉体が得られるので、比表面
積の増加すなわち高活性化につながり、メタンなどの安
定なガスをも検知できる材料を得ることができるという
利点があるθしかしながら、水溶液法でもその方法によ
っては種々の問題がある。たとえば共沈法の場合は、沈
殿剤が溶液に加えられるとき、たとえその濃度が薄く、
かつ溶液をじゅうぶんに攪拌しながら添加したとしても
、部分的には一時沈殿剤が高濃度になり、結晶核の生成
が速められ没殿粒子の大きさが不均一にな９、あるいは
凝結を起こすということがある。これが結果的には素子
間のバラツキを大きくしたり、課電寿命試験等における
特性劣化を促進したりする原因となっていた。For this reason, an aqueous solution method (coprecipitation method, homogeneous precipitation method, etc.) is an effective manufacturing method. This method has the advantage that not only is dispersion mixing excellent, but fine particle powder can be obtained, which leads to an increase in specific surface area, that is, high activation, and it is possible to obtain a material that can detect stable gases such as methane. However, even the aqueous solution method has various problems depending on the method. For example, in the coprecipitation method, when the precipitant is added to the solution, even if its concentration is dilute,
In addition, even if the solution is thoroughly stirred when added, the concentration of the precipitant may temporarily become high in some areas, accelerating the formation of crystal nuclei, causing uneven size of precipitated particles9, or causing coagulation. There is a thing. This has resulted in increased variations between elements and accelerated characteristic deterioration in energized life tests and the like.
発明の目的
本発明はこれら従来方法の欠点を解消し、凝結のない均
一な沈殿粒子を得ることによってガス感応体材料の均質
化を図シ、結果として素子間のばらつきが少なく、課電
寿命特性が大幅に改善されたガス検知素子を提供しよう
とするものである。Purpose of the Invention The present invention eliminates the drawbacks of these conventional methods and aims to homogenize the gas sensor material by obtaining uniform precipitated particles without agglomeration, resulting in less variation between elements and improved charging life characteristics. The present invention aims to provide a gas sensing element that is significantly improved.
発明の構成
本発明は種々の沈殿剤あるいはその他の製造工程に関す
る一連の検討の結果なされたもので、鉄イオンおよび陰
イオンとして少なくとも硫酸イオンを含む水溶液に尿素
（（ＮＨｚ ）２ Ｇｏ ’Ｊ を加え、これを加熱
することにより、この尿素の緩慢な加水分解によるｐＨ
のゆるやかな上昇を利用して、均−目ρ均質な粒子の調
整を可能としたもの士ある。Structure of the Invention The present invention was made as a result of a series of studies regarding various precipitants and other manufacturing processes. , by heating this, the pH due to slow hydrolysis of this urea
It has been possible to prepare particles with a uniform grain size by taking advantage of the gradual increase in .
実施例の説明
以下に本発明による効果について、比較例と対比させな
がらいくつかの実施例を用いて説明する。DESCRIPTION OF EXAMPLES The effects of the present invention will be explained below using several examples while comparing them with comparative examples.
〔比較例１〕
市販の塩化第二鉄（ＦｅＣｌ３・６Ｈ２０） ８０ ｑ
と硫酸アンモニウムＣ（ＮＨ４）２ ＳＯ４：ｌ ４ｏ
ｑをそれぞれ１℃の水に溶かし、８０’Ｃ，に保ぢな
がら攪拌した。さらに温度を８０°Ｃに保ちつつ、この
溶液に８規定の水酸化アンモニウム（ＮＨ４ＯＨ）溶液
を６０ ｃｃ１分の割合で溶液の水素イオン濃度が行に
なる寸で滴下した。滴下終了後、１０分間溶液の温度を
６０℃に保持し、との共沈物を吸引＆’過しだ。このよ
うにして得られた粉体を減圧容器に入れて真空乾燥を行
なった。得られた乾燥物をらいかい機で２時間粉砕した
後、有機バインダーを用いて１００〜２００μｍの大き
さの粒子に整粒した。この粉体に２本の白金線を埋め込
んで、直径２謳、高さ３語の円柱状に加圧成型し、空気
中において６５０℃で２時間の焼成を行なった。得られ
た多孔質の焼結体を検知素子用ベースにとりつけ、焼結
体のまわりにコイル状のヒータを配置し、防爆用のステ
ンレス鋼網をかぶせて検知素子を？Ｕた。[Comparative Example 1] Commercially available ferric chloride (FeCl3.6H20) 80 q
and ammonium sulfate C(NH4)2 SO4:l 4o
q was dissolved in water at 1°C, and stirred while maintaining the temperature at 80'C. Further, while maintaining the temperature at 80° C., 8N ammonium hydroxide (NH4OH) solution was added dropwise to this solution at a rate of 60 cc/min until the hydrogen ion concentration of the solution was equal to the line. After the dropwise addition was completed, the temperature of the solution was maintained at 60° C. for 10 minutes, and the coprecipitate was aspirated and filtered. The powder thus obtained was placed in a vacuum container and vacuum dried. The obtained dried product was pulverized for 2 hours using a grinder, and then sized into particles having a size of 100 to 200 μm using an organic binder. Two platinum wires were embedded in this powder, which was press-molded into a cylinder shape with a diameter of 2 mm and a height of 3 mm, and fired at 650° C. for 2 hours in air. The resulting porous sintered body is attached to a sensing element base, a coil-shaped heater is placed around the sintered body, and an explosion-proof stainless steel mesh is covered to form a sensing element. Uta.
第１図はガス検知素子の構造を示したものである。図に
おいて、１は焼結体で、２本の白金線からなる電極３，
４が埋め込まれている。２は焼結体１を力１１熱するた
めのヒータで、ヒータ用ビン１１．１２からヒータ用フ
レーム７．８ｔ−ｎじてヒータに電力が供給される。焼
結体１の抵抗は電極３，４からフレーム５，６を通じて
ビン９． 。FIG. 1 shows the structure of a gas detection element. In the figure, 1 is a sintered body, electrode 3 made of two platinum wires,
4 is embedded. Reference numeral 2 denotes a heater for heating the sintered body 1 by force 11, and power is supplied to the heater from heater bins 11.12 through heater frames 7.8t-n. The resistance of the sintered body 1 is measured from the electrodes 3, 4 through the frames 5, 6 to the bottle 9. .
１ｏの間で測定されるよう構成されている。ヒータ用ピ
ン１１．ｉ２およびビン９，１ｏはベース１３に固定さ
れ、ステンレス鋼製金網１４はベースにとシつけられて
いる。1o. Heater pin 11. i2 and bottles 9 and 1o are fixed to a base 13, and a stainless steel wire mesh 14 is attached to the base.
以上のようにして有られた検知素子について、ガス感応
特性、通常使用温度（４ｏｏ℃）での課型寿命および通
常使用する温度よりもはるかに高い温度（６００’Ｃ，
）での過負荷課電寿命を調べた。Regarding the detection element prepared as described above, the gas sensitivity characteristics, the life expectancy at the normal operating temperature (400°C), and the temperature much higher than the normal operating temperature (600°C,
), the overload lifespan was investigated.
ガス感応特性の測定方法は、あらかじめ検知素子のヒー
タ部に電流を流し、感応体の温度が４００”Ｃになるよ
うに調整しておき、それを容積の知られている測定箱内
に挿入した後、注射器でテスト用ガスを測定箱内に注入
し、焼結感応体の抵抗値を測定した。通常課電寿命は、
検知素子のヒータ部に常に電流を流し感応体の温度を４
００℃に保持し、経過時間とともに、上述の方法でガス
感応特性を測定し、メタン（ＯＨ，）と水素（Ｈ２）の
抵抗経時変化率、すなわち（初期の抵抗Ｒｇ（ｓｏｏｏ
ｐｐｍ）−を時間通電後の抵抗Ｒｑ（５０ＱＯｐｐｍ）
ｌ／初期の抵抗Ｒｑ （５０００ｐｐｍ）の値ΔＲ／Ｒ
（％）を求めた。過負荷課電１ｊ命については、感応体
の温度を通常の動作温度（４００°″Ｃ）よりもはるか
に高い６００℃に保持し、経過時間とともに、上記した
方法で測定し、通常課電寿命と同じ方法で抵抗経時変化
率を求めた。初期ガス感応特性および検知素子６０個中
の標準偏差を後掲の表の試料ＡＡの欄に、通常課電寿命
におけるＣＨ４に対する抵抗変化率の推移を第２図に、
寸たＨ２に対するそれを第３図に、また過負荷課電Ｒ命
におけるＯＨ４に対する抵抗変化率の推移を第４図に、
またＨ２に対するそれを第６図にそれぞれ示した。この
比較例１における実験結果は各図においてそれぞれ試料
ＡＡで示しである。The method for measuring gas sensitivity characteristics was to apply a current to the heater part of the sensing element in advance, adjust the temperature of the sensing element to 400"C, and then insert it into a measurement box with a known volume. After that, test gas was injected into the measurement box using a syringe, and the resistance value of the sintered sensitive body was measured.
A current is constantly applied to the heater part of the sensing element to raise the temperature of the sensitive element to 4.
The temperature was maintained at 00°C, and the gas sensitivity characteristics were measured using the method described above over time.
ppm)-resistance Rq after time energization (50QOppm)
l/value of initial resistance Rq (5000ppm) ΔR/R
(%) was calculated. Regarding overload charging life, the temperature of the sensitive body is maintained at 600°C, which is much higher than the normal operating temperature (400°"C), and the normal charging life is measured by the method described above over time. The rate of change in resistance over time was determined using the same method as above.The initial gas sensitivity characteristics and the standard deviation of 60 sensing elements are shown in the column for sample AA in the table below, and the change in rate of resistance change with respect to CH4 during the normal energized life is calculated. In Figure 2,
Figure 3 shows the resistance change rate for OH4 during overload energization, and Figure 4 shows the change in resistance change rate for OH4 during overload energization.
Further, the values for H2 are shown in FIG. The experimental results for Comparative Example 1 are indicated by sample AA in each figure.
第１表および第２図、第３図、第４図、第５図かられか
ることは、通常課電寿命および過負荷課電寿命において
、ＣＨ４に対しては抵抗が正側すなわち劣化傾向に、Ｈ
２ガスに対しては負側すなわち増感傾向に大幅に変化す
るため、このままでは実際の警報器に取シ付けて使用す
ることは、直接検知濃度の変化につながるので好ましく
ないことがわかる。また検知素子５０個中のばらつきも
相当大きいことがわかる。What can be seen from Table 1 and Figures 2, 3, 4, and 5 is that during normal energization life and overload energization life, the resistance for CH4 is on the positive side, that is, it tends to deteriorate. ,H
For two gases, there is a significant change in the negative side, that is, a tendency towards sensitization, so it can be seen that it is undesirable to attach it to an actual alarm device and use it as it is, as this will directly lead to a change in the detected concentration. It can also be seen that the variation among the 50 sensing elements is quite large.
なお、表中又は平均値、Ｓは標準偏差を示し、Ｒａは通
常の空気中における抵抗値である。In addition, in a table or an average value, S shows a standard deviation, and Ra is a resistance value in normal air.
〔比較例２〕
市販の硫酸第２鉄アンモニウム
（Ｆｅ２（ＳＯ２）、 （、ＮＨ４）２Ｓｏ４−２４Ｈ
２０）９ ｅ ｇを１１！、の水に溶かし、以下比較例
１と同様の方法で沈殿生成から検知素子の作成およびガ
ス感応特性の評価を行なった。初期ガス感応特性を後掲
の表の試料ＡＢのＩＬＩＩに、寸た課電寿命および過負
荷課電’Ｊ７命の抵抗変化率の推移を第２図〜第５図に
、それぞれ試料ＡＢで示した。[Comparative Example 2] Commercially available ferric ammonium sulfate (Fe2(SO2), (,NH4)2So4-24H
20) 9 e g to 11! , and the same method as in Comparative Example 1 was used to prepare a detection element and evaluate the gas sensitivity characteristics from the formation of a precipitate. The initial gas sensitivity characteristics are shown in ILII of sample AB in the table below, and the changes in resistance change rate during energization life and overload energization 'J7 life are shown in Figures 2 to 5, respectively, for sample AB. Ta.
表および第２図〜第５図かられかることは、通常課電寿
命および過負荷課電寿命において、ＯＨ４に対しては抵
抗が正側すなわち劣化傾向に、Ｈ２に対しては負側すな
わち増感傾向に大幅に変化するため、このま１では実際
の警報器に取り伺けて使用することは、直接検知濃度の
変化につながるので好ましくないことがわかる。また検
知素子６０個中のばらつきも相当大きいことがわかる。What can be seen from the table and Figures 2 to 5 is that during normal energization life and overload energization life, the resistance tends to be positive for OH4, that is, it tends to deteriorate, and for H2, it is on the negative side, that is, it increases. It is clear that it is undesirable to use an actual alarm device for the time being, as this will lead to a direct change in the detected concentration. It can also be seen that the variation among the 60 sensing elements is quite large.
〔実施例１〕
市販の塩化第２鉄８０ｑと硫酸アンモニウム４０ ｇお
よび尿素［（ＮＨ２）、、 Ｇｏ ：］６０ ｇを１ｐ
、の水に溶かし、ホットプレート」二で加熱しながら攪
拌した。加熱は９６℃以上で３時間行なった。この時の
水素イオン濃度（ｐＨ）は７．０であった。以下比較例
１と同様の方法で吸引ろ過から検知素子の作成およびガ
ス感応特性の評価を行なった。初期ガス感応特性を後掲
の表の試料ｊθＣの欄に、また課電寿命および過負荷課
電ノ予命の抵抗変化率の推移を第２図〜第５図の中の試
料１６ Ｇでそれぞｇ示した。[Example 1] 1 p of commercially available 80 q of ferric chloride, 40 g of ammonium sulfate, and 60 g of urea [(NH2), Go:]
Dissolved in water and stirred while heating on a hot plate. Heating was performed at 96° C. or higher for 3 hours. The hydrogen ion concentration (pH) at this time was 7.0. Thereafter, in the same manner as in Comparative Example 1, suction filtration was performed to produce a sensing element and evaluation of gas sensitivity characteristics. The initial gas sensitivity characteristics are shown in the sample jθC column in the table below, and the changes in resistance change rate during the life of energization and the expected life of overload energization are shown for sample 16G in Figures 2 to 5. I showed it.
以上の結果より、通常課電寿命および過負荷課電寿命に
おいて、比較例に比べて特性が著しく安定に推移してい
ることが判る。１だ検知素子５０個中のばらつきも大幅
に減少していることが判る。From the above results, it can be seen that the characteristics are extremely stable compared to the comparative example in the normal energization life and the overload energization life. It can be seen that the variation among the 50 detection elements is also significantly reduced.
〔実施例２〕
市販の硫酸第２鉄アンモニウム９６ｑと尿素６０ｑを１
１１の水に溶かし、ホットプレート」−で加熱しながら
攪拌した。以下実施例１と同様の方法で処理を行ない、
吸引ろ過から検知素子の作成およびガス感応特性の評価
を行なった。初期ガス感応特性を後掲の表の試料７６
Ｄの欄に、丑だ寿命試験の抵抗変化率の推移を第２図〜
第５図の中の試料Ｊ６ Ｄでそれぞれ示した。[Example 2] Commercially available ferric ammonium sulfate 96q and urea 60q
11 in water and stirred while heating on a hot plate. The following treatment was carried out in the same manner as in Example 1,
We created a sensing element using suction filtration and evaluated its gas sensitivity characteristics. The initial gas sensitivity characteristics are shown in the table below for sample 76.
In column D, the change in resistance change rate during the Ushida life test is shown in Figure 2.
These are respectively shown as sample J6D in FIG.
以上の結果より、通常課電寿命および過負荷課電寿命に
おいて、比較例に比べて特性が著しく安定に推移してい
ることがわかる。また検知素子６０個中のばらつきも大
幅に減少していることがわかる。From the above results, it can be seen that the characteristics are extremely stable compared to the comparative example in the normal energization life and the overload energization life. It can also be seen that the variation among the 60 sensing elements is significantly reduced.
（以下余白）
なお、上記各実施例においては、加圧成型体を焼結して
得られた感応体を用いた素子の場合について説明したが
、本発明は感応体が」二連のような加圧成型された焼結
体の場合にのみ有効であるのではなく、例えばこの焼結
体原料をペースト化して基板上に塗布し、焼きつけて得
られる焼結膜を感応体として用いた場合についても本発
明の効果は何ら失なわれるものではない、。(Left below) Note that in each of the above embodiments, the case of an element using a sensitive body obtained by sintering a pressure-molded body was explained, but in the present invention, the sensitive body is It is effective not only for pressure-molded sintered bodies, but also for cases where the sintered body raw material is made into a paste, coated on a substrate, and the resulting sintered film is used as a sensitive body. The effects of the present invention are not lost in any way.
また原料塩については、比較例１と実施例１では塩化第
２鉄を用いて説明したが、これに限らず水溶性の鉄塩（
塩化第１鉄や硫酸第１．第２鉄等）ならば全て有効であ
る。まプこ、比較例２と実施例２については硫酸第２鉄
アンモニウムを用いて説明したが、これに限らず水溶性
の（希酸鉄塩（硫酸 。Regarding the raw material salt, although ferric chloride was used in Comparative Example 1 and Example 1, this is not limited to this, and water-soluble iron salts (
Ferrous chloride and sulfuric acid. 2nd railway, etc.), all are valid. Mapco, Comparative Example 2 and Example 2 were explained using ferric ammonium sulfate, but the invention is not limited to this, and water-soluble (dilute acid iron salts (sulfuric acid).
第１．第２鉄や硫酸第１鉄アンモニウｌ、等）を用いて
も全て有効である。1st. It is also effective to use ferric iron, ferrous ammonium sulfate, etc.).
丑た、実施例においては５５０℃で焼成を行なった場合
について述べたが、この焼成温度は特に限定されるもの
ではなく、実用−ヒ耐えうる焼結体強度を持つ焼成温度
であればよい。In the examples, the firing was performed at 550°C, but the firing temperature is not particularly limited, and may be any firing temperature that provides a strength of the sintered body that can withstand practical use.
発明の効果
以上詳細に述べたように、本発明の製造方法は尿素の加
水分解を利用した沈殿生成反応をガス感応体の原料粉末
の調製にたくみに応用したものであり、得られた粉体の
粒子形状、粒子径が極めて均一であるため各検知素子間
のガス感応特性のばらつきが非常に小さく、かつ長期間
の高温動作に対してもきわめて安定な特性を卸持するこ
とのできる素子を提供するものである。これによって、
互換性のある、しかも非常に信頼性の高い可燃性ガス検
知素子を実現することができ、各種のガス防災技術の分
野に対して極めて大きな貢献ができるものと期待される
。Effects of the Invention As described in detail above, the production method of the present invention skillfully applies a precipitation reaction using urea hydrolysis to the preparation of raw material powder for a gas sensitive material, and the resulting powder Because the particle shape and particle size are extremely uniform, the variation in gas sensitivity characteristics between each sensing element is extremely small, and the element can maintain extremely stable characteristics even during long-term high-temperature operation. This is what we provide. by this,
It is possible to realize a compatible and highly reliable combustible gas detection element, and it is expected that it will make an extremely large contribution to the field of various gas disaster prevention technologies.
第１図は本発明にかかる可燃性ガス検知素子の構造の一
例を示す正面図、第２図、第３図は通電課電寿命におけ
るガス検知素子の抵抗値の初期値に対する変化率の推移
を示す図、第４図、第６図は過負荷課電寿命におけるガ
ス検知素子の抵抗値の変化率を示す図である。
１・・・・・・焼結体、２・・・・ヒータ、３，４・・
・・・・電極、５，６，７．８・・・・・・フレーム、
９．１０・・・・・・電極用ピン、１１．１２・・・・
・・ヒータ用ピン、１３・・・・・・ペース、１４・・
・・・・ステンレス’ＪＪ−金Ｍ’３ 。
代理人の氏名 弁理士 中 尾 敏 男 ほか１名第１
図FIG. 1 is a front view showing an example of the structure of a combustible gas detection element according to the present invention, and FIGS. 2 and 3 show changes in the rate of change of the resistance value of the gas detection element with respect to its initial value over the life of energization. The figures shown in FIGS. 4 and 6 are diagrams showing the rate of change in the resistance value of the gas detection element during the life of overload application. 1... Sintered body, 2... Heater, 3, 4...
... Electrode, 5, 6, 7.8 ... Frame,
9.10... Electrode pin, 11.12...
...Heater pin, 13...Pace, 14...
...Stainless Steel 'JJ-Gold M'3. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
figure
Claims (2)
オンを含む水溶液に尿素（（ＮＨ２）２ ｃｏ）を加え
、これを加熱することによって得られる沈殿物を乾燥し
てガス感応体材料を得ることを特徴とするガス感応体材
料の製造方法。(1) A gas sensitizer material is obtained by adding urea ((NH2)2co) to an aqueous solution containing iron ions and at least sulfate ions as anions, and drying the precipitate obtained by heating the solution. A method for producing a gas sensitive material.
ことによって得られる沈殿物を乾燥してガス感応体材料
をイ４）ることを特徴とする特許請求の範囲第（１）項
記載のガス感応体材料の製造方法。(2) Adding urea to an aqueous solution of iron sulfate salt and heating the resulting precipitate is dried to obtain a gas sensitive material (4). Claim (1) A method for producing the gas susceptor material described above.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57144512A JPS5934140A (en) | 1982-08-19 | 1982-08-19 | Manufacture of material of gas-sensitive body |
| US06/496,492 US4732738A (en) | 1982-05-17 | 1983-05-17 | Combustible gas detecting element |
| DE8383302807T DE3379481D1 (en) | 1982-05-17 | 1983-05-17 | Combustible gas-detecting element and its production |
| EP83302807A EP0095313B1 (en) | 1982-05-17 | 1983-05-17 | Combustible gas-detecting element and its production |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57144512A JPS5934140A (en) | 1982-08-19 | 1982-08-19 | Manufacture of material of gas-sensitive body |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5934140A true JPS5934140A (en) | 1984-02-24 |
| JPS628136B2 JPS628136B2 (en) | 1987-02-20 |
Family
ID=15364077
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57144512A Granted JPS5934140A (en) | 1982-05-17 | 1982-08-19 | Manufacture of material of gas-sensitive body |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5934140A (en) |
-
1982
- 1982-08-19 JP JP57144512A patent/JPS5934140A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS628136B2 (en) | 1987-02-20 |
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