JPS5817428B2 - Gasken Chisoshi - Google Patents
Gasken ChisoshiInfo
- Publication number
- JPS5817428B2 JPS5817428B2 JP49035570A JP3557074A JPS5817428B2 JP S5817428 B2 JPS5817428 B2 JP S5817428B2 JP 49035570 A JP49035570 A JP 49035570A JP 3557074 A JP3557074 A JP 3557074A JP S5817428 B2 JPS5817428 B2 JP S5817428B2
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- JP
- Japan
- Prior art keywords
- gas
- sensitivity
- concentration
- gases
- detection
- 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
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- Investigating Or Analyzing Materials By The Use Of Fluid Adsorption Or Reactions (AREA)
Description
【発明の詳細な説明】
本発明は、金属酸化物、特に錫の酸化物を主成分とする
ガス検知素子に関するものであり、特に、高濃度のＣＯ
ガス等の主として高濃度可燃性ガスの測定検出に適した
ガス検知素子である。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a gas detection element containing a metal oxide, particularly a tin oxide, as a main component, and particularly relates to a gas detection element containing a metal oxide, particularly a tin oxide.
This is a gas detection element suitable for measuring and detecting mainly high concentration combustible gases such as gases.
従来、可燃性ガスの検知は、錫の酸化物を主体とした素
子が検知感度が高く広く使用されており、さらに、Ｐｄ
、 Ｐｔ、 Ｃｏ、 Ｎｉ等を添加して検知感度を向上
させ、また、これら原料の製造工程中で塩素が残留する
ようにしてＣＯガスに対する感度を向上させ、さらに、
Ａｌ２Ｏ３、ＺｎＯ１ＳｒＯ，ＢａＯ等を５ｗｔ％以下
添加することにより、ＣＯガスに対し選択的に高い感度
を有する素子を得ることができ、室内暖房等によるＣＯ
ガスの増加や、大気中のＣＯガスの量を敏感に検出でき
るような素子が提案され、実施されるようになってきて
いる。Conventionally, elements mainly made of tin oxide have been widely used to detect flammable gases due to their high detection sensitivity.
, Pt, Co, Ni, etc. are added to improve the detection sensitivity, and chlorine remains during the manufacturing process of these raw materials to improve the sensitivity to CO gas.
By adding 5 wt% or less of Al2O3, ZnO1SrO, BaO, etc., it is possible to obtain an element with high sensitivity selectively to CO gas, and it is possible to obtain an element that has high sensitivity selectively to CO gas.
Elements that can sensitively detect the increase in gas and the amount of CO gas in the atmosphere have been proposed and are being put into practice.
また、最近になって、自動車の排気ガスによる大気の汚
染が問題となり、極めて厳しい排気ガス規制が実施され
ることになり、排気ガス中のＣＯ濃度の測定を簡単容易
に行なうことのできるガス検知素子が要求されているが
、上記したようなＣＯガスを選択的に検知測定できるガ
ス検知素子も高い濃度のＣＯガスの測定には適さず、１
０００購程度までが限度であり、排気ガス中のｃｏ濃度
の検知測定のように１〜３％の濃度では、検知素子の抵
抗値の変化率が少なく検知測定が困難であった。In addition, recently, air pollution caused by automobile exhaust gas has become a problem, and extremely strict exhaust gas regulations have been implemented. However, gas detection elements such as those described above that can selectively detect and measure CO gas are not suitable for measuring high concentrations of CO gas.
The limit is about 1,000 units, and at a concentration of 1 to 3%, as in the case of detecting and measuring the cobalt concentration in exhaust gas, the rate of change in the resistance value of the detecting element is small, making detection and measurement difficult.
本発明は、上記に説明したような従来のガス検知素子の
欠点を解決したものであって、特に、高い濃度のＣＯガ
ス等の測定に適したガス検知素子であり、即ち、錫の酸
化物を主成分とし、これにＡｌ２Ｏ３，５ｒＯ１ＢａＯ
の１種または１種以−Ｌを５ｗｔ％以上含有させること
を特徴とするものである。The present invention solves the drawbacks of the conventional gas detection elements as explained above, and is a gas detection element particularly suitable for measuring high concentration CO gas, etc. The main component is Al2O3,5rO1BaO
It is characterized by containing 5 wt% or more of one or more types of -L.
次に、本発明について具体的に説明する。Next, the present invention will be specifically explained.
一般に、錫の酸化物（５ｎ０２ ）を主体とした金属酸
化物のガス検知素子は、可燃性ガスの検知に適している
が、これに、Ｐｄ、 Ｐｔ、 Ｃｏ、 Ｎｉ等を添加し
て感度をさらに高めるようにしており、これらの添加物
の量は２ｗｔ％以下で、特に、０．２ｗｔ％〜０．０１
ｗｔ％の範囲が顕著な効果を示しているが、この検知素
子は、可燃性ガスでも、エタン、メタン、プロパン、イ
ソブタンおよび水素に対して、特に良好な感度を有する
。In general, metal oxide gas detection elements mainly made of tin oxide (5n02) are suitable for detecting flammable gases, but they can be added with Pd, Pt, Co, Ni, etc. to increase sensitivity. The amount of these additives is 2wt% or less, especially 0.2wt% to 0.01wt%.
The sensing element has particularly good sensitivity for combustible gases such as ethane, methane, propane, isobutane and hydrogen, although a range of wt% shows a significant effect.
しかし、ＣＯガスに対しては感度が悪いのである。However, it has poor sensitivity to CO gas.
そのため、原料。の製造工程中において塩素を残留させ
るようにして、組成中に２ｗｔ％以下の塩素が含まれる
ようにした素子を開発し、この素子は、エタン、メタン
、プロパン、イソブタン、水素等のｉ■燃性ガスと殆ん
ど同程度にＣＯガスに対する検知感度を高ｊめることか
できるようになった。Therefore, raw materials. We have developed an element that contains 2 wt% or less of chlorine in the composition by allowing chlorine to remain during the manufacturing process. It has become possible to increase the detection sensitivity for CO gas to almost the same level as for carbon dioxide gas.
また、上記に説明した素子に、Ａｌ２Ｏ３，５ｒＯ１Ｂ
ａＯ等を５ｗｔ％以下含有させることによって、エタン
、メタン、プロパン、イソブタン、ベンセン、アルコー
ル等に対する感度をおさえ、ＣＯガスに選択的に感度。In addition, Al2O3, 5rO1B
By containing 5wt% or less of aO, etc., the sensitivity to ethane, methane, propane, isobutane, benzene, alcohol, etc. is suppressed, and the sensitivity is selectively sensitive to CO gas.
を高めることも提案されている。It has also been proposed to increase
しかしながら、以上説明したガス検知素子は、何れもＣ
Ｏガスに対しては、１０〜１０００ｐｐＩｎ程度におい
て極めて高い感度を有し、大気中のＣＯガスによる環境
汚染、室内暖房等による室内空気シのＣＯガスの増加を
検知する場合には適しているが、これは低濃度ガスには
高い感度を有するが、高濃度のＣＯガス、例えは、自動
車の排気ガスのようにＣＯガスが０．５〜３％になると
測定は不可能であった。However, all of the gas detection elements described above are
It has an extremely high sensitivity to O gas in the range of 10 to 1000 ppIn, and is suitable for detecting environmental pollution caused by CO gas in the atmosphere and increases in CO gas in the indoor air due to indoor heating, etc. Although this method has high sensitivity for low-concentration gases, it is impossible to measure high-concentration CO gases, for example, CO gases of 0.5 to 3%, such as automobile exhaust gas.
本発明においては、以上説明したように事実に鑑みて、
Ａｌ２Ｏ３，５ｒＯ１ＢａＯの１種または１種以上を、
錫の酸化物を主成分とする素子にその添加割合を変化さ
せて特性を測定したところ、上記酸化物、即ち、Ａｌ２
Ｏ３，５ｓＯ１ＢａＯの１種また。In the present invention, in view of the facts as explained above,
One or more types of Al2O3, 5rO1BaO,
When we measured the characteristics of a device whose main component was tin oxide by changing its addition ratio, we found that the above oxide, that is, Al2
Also one type of O3,5sO1BaO.
は１種以上を５ｗｔ％以上含有させると、添加量が増加
するに従って検知ガスの種類に選択性を有するようにな
るが、段々と感度が低くなり、低濃度のガスの検知素子
としては効果が少なくなってくる。When 5wt% or more of one or more types is contained, as the amount added increases, the type of sensing gas becomes more selective, but the sensitivity gradually decreases, making it ineffective as a sensing element for low-concentration gases. It's getting less.
しかし、ガス濃度の高い領域についての特性は、感度飽
和域が次第に高くなり３％以上のＣＯガスに対してもそ
の濃度に応じて検知出力が高くなるものである。However, the characteristic of a region with a high gas concentration is that the sensitivity saturation region gradually increases, and the detection output increases in accordance with the concentration even for CO gas of 3% or more.
本発明の詳細な説明する。The present invention will be described in detail.
実施例 １
５ｎＣ１４とＡｌ２Ｏ３として８ｗｔ％となる量のＡｌ
（ＮＯ３）３およびＰｄＣｌ２０．０２ｗｔ％の水溶液
にＮＨ４ＯＨ水溶液を添加して中和し、沈澱物を４５０
〜５５０℃で仮焼した。Example 1 5nC14 and Al in an amount of 8 wt% as Al2O3
(NO3)3 and PdCl20.02wt% aqueous solution was neutralized by adding NH4OH aqueous solution, and the precipitate was
Calcined at ~550°C.
この仮焼した物質には、Ａｌ２Ｏ３が８ｗｔ％含有して
おり、この仮焼物質を粉砕して水と粘結剤、例えは、澱
粉を混合して塗布し易い状態として検知素子基体に膜状
に塗布し、乾燥し、さらに、５５０℃の温度で焼結した
。This calcined material contains 8 wt% of Al2O3, and this calcined material is pulverized and mixed with water and a binder, such as starch, to form a film on the sensing element substrate. It was coated, dried, and then sintered at a temperature of 550°C.
このようにして製造されたガス検知素子は、プロパン、
メタン等には感度は殆んどなく、ＣＯ高濃度ガスには優
れた感度を示したのである。The gas detection element manufactured in this way can contain propane,
It had almost no sensitivity to methane, etc., but showed excellent sensitivity to CO-concentration gases.
これを図により示すと、第１図の曲線１のような特性を
示す。If this is illustrated graphically, it exhibits characteristics like curve 1 in FIG.
また、同様な製法によって、Ａｌ２Ｏ３を３５ｗｔ％含
むガス検知素子の特性を第１図の曲線２に示す。Further, curve 2 in FIG. 1 shows the characteristics of a gas sensing element containing 35 wt % Al2O3 produced by a similar manufacturing method.
実施例 ２
Ｓｎ０２５００ ｇ、塩酸２５０ＣＣ（２５％溶液）、
ＢａＣＯ３７５ｇ（Ｓ００２に対して１５ｗｔ％）を充
分に混合した後、仮焼を行ない、検知素子基体に塗布乾
燥後焼結すると、ＳｎＯ□を主成分とするＢａＯを約１
２ｗｔ％含む素子が得られた。Example 2 500 g of Sn0, 250 cc of hydrochloric acid (25% solution),
After sufficiently mixing 375 g of BaCO (15 wt% with respect to S002), calcination is performed, applied to the sensing element substrate, dried, and sintered.
A device containing 2 wt% was obtained.
この素子のＣＯガスに対する特性を第２図に示す。The characteristics of this element with respect to CO gas are shown in FIG.
実施例 ３
ＳｎＣＩ４とＡｌ（ＮＯ３）３およびＳ ｒ （ＮＯ３
）２の水溶液に、これらの総量に対し約０．１ｗｔ％の
ＰｄＣｌ２を加えＮＨ４ＯＨ水溶液を添加して中和し沈
澱物を４５０〜５５０℃で仮焼し、仮焼物中のＳｎＯ□
に対してＡｌ２Ｏ３が４ｗｔ％、ＳｒＯが７ｗｔ％を含
むようにし、この仮焼物を粉砕して水と粘結剤を加えて
塗布し易い粘度として検知素子基体に塗布乾燥後焼結し
た素子は、ＣＯガス１％および２％に対する素子抵抗値
をＲ１、Ｒ２とし、空気中の素子抵抗値をＲ６とじたと
き、Ｒ，／’Ｒｏ＝３．２、Ｒ２／Ｒｏ＝ ５．５とな
り、ＣＯガスの高濃度に対して優れた感度を有する素子
が得られた。Example 3 SnCI4 and Al(NO3)3 and S r (NO3
) 2, about 0.1 wt% of PdCl2 based on the total amount thereof was added, neutralized by adding NH4OH aqueous solution, and the precipitate was calcined at 450 to 550°C to remove SnO□ in the calcined product.
4 wt% of Al2O3 and 7 wt% of SrO, and the calcined material is crushed and water and a binder are added to make it have a viscosity that is easy to coat.The element is coated on the sensing element substrate after drying and sintered. When the element resistance values for 1% and 2% CO gas are R1 and R2, and the element resistance value in air is R6, R,/'Ro=3.2, R2/Ro=5.5, and CO gas A device with excellent sensitivity to high concentrations of was obtained.
実施例 ４
ＳｎＣ１４、Ｂａ（ＮＯ３）２およびＳｒ（ＮＯ３）２
の水溶液に、これらの総量に対し約０．１ｗｔ％のＰｄ
Ｃｌ２を加えＮＨ４ＯＨ水溶液を添加して中和し、沈澱
物を４５０〜５５０℃で仮焼し、仮焼物中の５ｎ０２に
対しＢａＯが４ｗｔ％、８ｒＯが８ｗｔ％を含むように
し、この仮焼物を粉砕して水と粘結剤を加えて塗布し易
い粘度にして検知素子基体に塗布乾燥後焼結した素子は
、ＣＯガス１％および２％に対する素子抵抗値をＲ１、
Ｒ２とし、空気中の素子抵抗値をＲ８とじたとき、Ｒ１
／Ｒ２・４３、Ｒ２／Ｒ８＝８．５となり、ＣＯガスの
高濃度に対して優れた″感度を有する素子が得られた。Example 4 SnC14, Ba(NO3)2 and Sr(NO3)2
About 0.1 wt% of Pd based on the total amount of Pd was added to the aqueous solution of
Cl2 is added and NH4OH aqueous solution is added to neutralize, and the precipitate is calcined at 450 to 550°C so that the 5n02 in the calcined material contains 4 wt% of BaO and 8 wt% of 8rO. The element is pulverized, added with water and a binder to a viscosity that is easy to apply, applied to the sensing element substrate, dried, and sintered.The element resistance against 1% and 2% CO gas is R1,
R2 and the element resistance value in the air is R8, then R1
/R2·43, R2/R8=8.5, and an element with excellent sensitivity to high concentrations of CO gas was obtained.
比較例
５ｎ０２を主成分とし、ＰｄＣｌ２を約０．０２ ｗｔ
％含有し、総塩素量０．５ｗｔ％の素子のＣＯガスに対
する特性を第３図に示す。Comparative Example 5n02 as the main component, PdCl2 about 0.02 wt
% and a total chlorine amount of 0.5 wt %, the characteristics with respect to CO gas are shown in FIG.
以上、説明した第１図〜第３図において、ＣＯガスの各
濃度に対する素子抵抗値Ｒｎの変化状況を空気中におけ
る素子抵抗Ｒ６との比で表わしたものである。In FIGS. 1 to 3 described above, the state of change in the element resistance value Rn for each concentration of CO gas is expressed as a ratio to the element resistance R6 in air.
各素子のＣＯガス１％と２％の場合の変化状況を各図か
ら判断して夫々の抵抗値の比Ｒ２／Ｒ１を求めたものを
示すと次表の通りである。The following table shows the ratio R2/R1 of the resistance values determined by determining the change status of each element in the case of 1% and 2% CO gas from each figure.
上記したように、本発明に係る実施例１および２によれ
ば、第１図および第２図に示されていることから明らか
なように、低濃度ＣＯガス１０〜１ｏｏｏｐｐｍｇこお
いては素子抵抗は顕著な変化は示さないが、高濃度ＣＯ
ガスに対し濃度に比例して素子抵抗が変化し、特に、ｉ
ｏｏｏｐｐｍ以上３０．０００ｐｐＩｌｌないし５０．
ＯＯＯｐｐｍまでの検出に顕著な変化を示す。As described above, according to Examples 1 and 2 according to the present invention, as is clear from FIGS. 1 and 2, when the low concentration CO gas is 10 to 1 oooppmg, does not show any significant change, but at high concentrations of CO
The element resistance changes in proportion to the gas concentration, especially i
oooppm or more 30,000ppIll to 50.
It shows a remarkable change in detection up to OOOppm.
このようなことは、第３図に示すような従来の素子に見
られない高濃度のＣＯガスの検出に適したものである。This is suitable for detecting a high concentration of CO gas, which is not found in conventional elements as shown in FIG.
さらに、表からも明らかであるが、従来の素子はＣＯガ
ス１％以上では抵抗値変化が鈍化してガス濃度が２倍と
なっても素子抵抗値は約１０％程度の変化に過ぎないた
め、安定な検出が不可能であったが、本発明に係る素子
は、この領域においても約１５〜２．１倍の変化を示し
、充分実用に供し得ると共に高濃度にも適用することが
できるものである。Furthermore, as is clear from the table, the change in resistance of conventional elements slows down when CO gas exceeds 1%, and even if the gas concentration doubles, the element resistance changes by only about 10%. However, the device according to the present invention shows a change of about 15 to 2.1 times in this region, and can be used for practical purposes and can be applied to high concentrations. It is something.
以上、詳細に説明したように、本発明に係るガス検知素
子によれば、高濃度ガス、特に、ＣＯガス等を検出する
ことができる優れた発明である。As described above in detail, the gas detection element according to the present invention is an excellent invention capable of detecting highly concentrated gases, particularly CO gas and the like.
第１図および第２図は本発明に係るガス検知素子のＲｎ
／Ｒｏを示すグラフ、第３図は従来の素子のＲｎ ／
Ｒｏを示すグラフである。FIGS. 1 and 2 show Rn of the gas detection element according to the present invention.
Graph showing /Ro, Figure 3 shows the Rn /Ro of the conventional element.
It is a graph showing Ro.
Claims (1)
Ｏ１ＢａＯの１種または１種以上を５ｗｔ％以上含有さ
せることを特徴とする高濃度ガス検知素子。1 The main component is tin oxide, and A12o3゜5r is added to this.
A high concentration gas sensing element characterized by containing 5 wt% or more of one or more types of O1BaO.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP49035570A JPS5817428B2 (en) | 1974-04-01 | 1974-04-01 | Gasken Chisoshi |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP49035570A JPS5817428B2 (en) | 1974-04-01 | 1974-04-01 | Gasken Chisoshi |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS50132995A JPS50132995A (en) | 1975-10-21 |
| JPS5817428B2 true JPS5817428B2 (en) | 1983-04-07 |
Family
ID=12445403
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP49035570A Expired JPS5817428B2 (en) | 1974-04-01 | 1974-04-01 | Gasken Chisoshi |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5817428B2 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS52145092A (en) * | 1976-05-27 | 1977-12-02 | Toshiba Corp | Preparation of gas-sensitive element |
| JPS52145096A (en) * | 1976-05-27 | 1977-12-02 | Toshiba Corp | Preparation of gas-sensitive element |
| JPS6345552A (en) * | 1986-08-13 | 1988-02-26 | Shinkosumosu Denki Kk | Gaseous carbon monoxide sensor |
| JP2595123B2 (en) * | 1990-07-06 | 1997-03-26 | 新コスモス電機株式会社 | Carbon monoxide gas sensor |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4874894A (en) * | 1971-12-30 | 1973-10-09 |
-
1974
- 1974-04-01 JP JP49035570A patent/JPS5817428B2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS50132995A (en) | 1975-10-21 |
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