JPH0318721B2 - - Google Patents
Info
- Publication number
- JPH0318721B2 JPH0318721B2 JP59014739A JP1473984A JPH0318721B2 JP H0318721 B2 JPH0318721 B2 JP H0318721B2 JP 59014739 A JP59014739 A JP 59014739A JP 1473984 A JP1473984 A JP 1473984A JP H0318721 B2 JPH0318721 B2 JP H0318721B2
- Authority
- JP
- Japan
- Prior art keywords
- oxide
- moisture
- humidity
- resistance element
- sensitive resistance
- 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 - Lifetime
Links
- 238000002844 melting Methods 0.000 claims description 16
- 230000008018 melting Effects 0.000 claims description 15
- 239000002131 composite material Substances 0.000 claims description 9
- 229910052783 alkali metal Inorganic materials 0.000 claims description 5
- 150000001340 alkali metals Chemical class 0.000 claims description 5
- 239000011777 magnesium Substances 0.000 claims description 5
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical group [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 claims description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 3
- -1 bihumuth oxide Chemical compound 0.000 claims description 3
- 229910052749 magnesium Inorganic materials 0.000 claims description 3
- 239000001301 oxygen Substances 0.000 claims description 3
- 229910052760 oxygen Inorganic materials 0.000 claims description 3
- JKWMSGQKBLHBQQ-UHFFFAOYSA-N diboron trioxide Chemical compound O=BOB=O JKWMSGQKBLHBQQ-UHFFFAOYSA-N 0.000 claims description 2
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical group [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 claims 1
- XHCLAFWTIXFWPH-UHFFFAOYSA-N [O-2].[O-2].[O-2].[O-2].[O-2].[V+5].[V+5] Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[V+5].[V+5] XHCLAFWTIXFWPH-UHFFFAOYSA-N 0.000 claims 1
- 229910052810 boron oxide Inorganic materials 0.000 claims 1
- 229910000464 lead oxide Inorganic materials 0.000 claims 1
- YEXPOXQUZXUXJW-UHFFFAOYSA-N oxolead Chemical compound [Pb]=O YEXPOXQUZXUXJW-UHFFFAOYSA-N 0.000 claims 1
- 229910001935 vanadium oxide Inorganic materials 0.000 claims 1
- 229910052725 zinc Chemical group 0.000 claims 1
- 239000011701 zinc Chemical group 0.000 claims 1
- 230000035945 sensitivity Effects 0.000 description 10
- 239000007789 gas Substances 0.000 description 8
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 8
- 239000000843 powder Substances 0.000 description 7
- 239000000779 smoke Substances 0.000 description 7
- 239000000463 material Substances 0.000 description 6
- 229910044991 metal oxide Inorganic materials 0.000 description 6
- 150000004706 metal oxides Chemical class 0.000 description 6
- 235000019504 cigarettes Nutrition 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 238000010438 heat treatment Methods 0.000 description 5
- 230000007423 decrease Effects 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 241000208125 Nicotiana Species 0.000 description 3
- 235000002637 Nicotiana tabacum Nutrition 0.000 description 3
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 3
- 238000010304 firing Methods 0.000 description 3
- 229910052709 silver Inorganic materials 0.000 description 3
- 239000004332 silver Substances 0.000 description 3
- 239000011734 sodium Substances 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- 229910015902 Bi 2 O 3 Inorganic materials 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229910052742 iron Inorganic materials 0.000 description 2
- HTUMBQDCCIXGCV-UHFFFAOYSA-N lead oxide Chemical compound [O-2].[Pb+2] HTUMBQDCCIXGCV-UHFFFAOYSA-N 0.000 description 2
- 239000011812 mixed powder Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000004570 mortar (masonry) Substances 0.000 description 2
- 229920000620 organic polymer Polymers 0.000 description 2
- WOCIAKWEIIZHES-UHFFFAOYSA-N ruthenium(iv) oxide Chemical compound O=[Ru]=O WOCIAKWEIIZHES-UHFFFAOYSA-N 0.000 description 2
- 229910052596 spinel Inorganic materials 0.000 description 2
- 239000011029 spinel Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- JBQYATWDVHIOAR-UHFFFAOYSA-N tellanylidenegermanium Chemical compound [Te]=[Ge] JBQYATWDVHIOAR-UHFFFAOYSA-N 0.000 description 2
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 1
- 239000004698 Polyethylene Substances 0.000 description 1
- 239000004372 Polyvinyl alcohol Substances 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 229910000416 bismuth oxide Inorganic materials 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 238000007791 dehumidification Methods 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- TYIXMATWDRGMPF-UHFFFAOYSA-N dibismuth;oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Bi+3].[Bi+3] TYIXMATWDRGMPF-UHFFFAOYSA-N 0.000 description 1
- GNTDGMZSJNCJKK-UHFFFAOYSA-N divanadium pentaoxide Chemical compound O=[V](=O)O[V](=O)=O GNTDGMZSJNCJKK-UHFFFAOYSA-N 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 1
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 description 1
- 229910052744 lithium Inorganic materials 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910000000 metal hydroxide Inorganic materials 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229920006122 polyamide resin Polymers 0.000 description 1
- 229920000573 polyethylene Polymers 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- 229910001925 ruthenium oxide Inorganic materials 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
Landscapes
- Investigating Or Analyzing Materials By The Use Of Fluid Adsorption Or Reactions (AREA)
- Non-Adjustable Resistors (AREA)
Description
本発明は、金属酸化物の焼結体からなり、相対
湿度変化を電気抵抗の変化として検出することが
でき、しかも空気中の雑ガスによる検出能劣化が
生じにくい感湿抵抗素子に関するものである。
一般に、感湿抵抗素子の受感部にはポリアミド
樹脂、ポリエチレン等の有機高分子、あるいは、
Fe2O3、Cr2O3等の金属酸化物が使用されている。
しかし、金属酸化物の方が有機高分子よりも、化
学的、物理的に比較的安定しており、感湿抵抗素
子用材料として有望である。しかし、通常の金属
酸化物は、固有抵抗が高いこと、湿度変化による
抵抗変化が小さいこと、しかも加湿−除湿の条件
下において湿度−抵抗特性にヒステリシスが存在
すること等の欠点を有し、そのままでは感湿抵抗
素子用材料として適当でなかつた。そこで、発明
者らは、０〜100％の相対湿度に対して、低抵抗
で、その値が２〜３桁変化し、高温、高湿雰囲気
下においても長期にわたつて特性が変化しない感
湿抵抗素子用材料として、M1-xAxFe2O4-〓系
｛ここに、Ｍ：マグネシウム（Mg）又は亜鉛
（Zn）、Ａ：アルカリ金属、すなわちリチウム
（Li）、ナトリウム（Na）、もしくはカリウム(k)、
Fe：鉄｝焼成材を見つけ出し、該材料を使用し
て、優れた感湿抵抗素子を製作し、既に出願した
（特願昭56−196534）。この素子は、比較的清浄な
室内において１年以上使用しても特性変動は極め
て小さいという特長を有する。
しかし、煙草の煙等、水分以外のガスにより汚
染された空気中に晒すと、素子の電気抵抗値が高
くなり、初期特性との間い食い違いが発生する。
この特性の食い違いは、素子を約400℃以上の
温度に数分間加熱すれば消滅する。しかし使用の
途中で、たびたび加熱処理を必要とするもので
は、素子に加熱用ヒータおよび制御用回路を組込
むことが必要となり、素子自体の構造が複雑にな
るなどの問題点があつた。
そこで、発明者らは、上記M1-xAxFe2O4-〓系
物質に低融点の金属酸化物を添加すると、この物
質が煙草の煙等、水分以外の雑ガスに対して不活
性になることの発見に基づき、上記従来の問題点
を克服した感湿抵抗素子を完成した。すなわち、
本発明は、M1-xAxFe2O4-〓｛但し、Ｍはマグネシ
ウム（Mg）又は亜鉛（Zn）、Ａはアルカリ金属、
0.001＜ｘ＜0.2、αは酸素空格子数、Feは鉄、Ｏ
は酸素｝により表わされる複合酸化物と、酸化ホ
ウ素（B2O3）、酸化ビスマス（Bi2O3）、酸化バナ
ジウム（V2O5）および酸化鉛（PbO）のうちか
ら少なくとも一種選ばれた低融点酸化物とからな
ることを特徴とする感湿抵抗素子である。
本発明にかかる感湿抵抗素子は、相対湿度変化
に対する電気抵抗変化が大きく、しかも特性にヒ
ステリミスが少ないことに加えて、極く少量の低
融点酸化物が存在しているために煙草の煙等の雑
ガスによる特性劣化が少ないという優れた性質を
有する。
以下、本発明をより詳細に説明する。
本発明にかかる感湿抵抗素子は、複合酸化物と
低融点酸化物とからなるものである。上記複合酸
化物はスピネルである「MFe2O4」のＭの0.1〜20
アトム％を、アルカリ金属で置換した形態を有
し、「M1-xAxFe2O4-〓」の一般式で表わされるも
のである。
ここに、ｘの値としては0.001〜0.2の範囲であ
り、この範囲内において良好な感湿特性を示す。
さらに、0.01〜0.05の範囲内の場合には、相対湿
度と電気抵抗値の対数との関係がほぼ直線比例と
なり、より使いやすい感湿抵抗素子とな。また、
αはアルカリ金属の量から決まる数値であつて、
その値は約ｘ／２であるる。
一方、上記低融点酸化物は、B2O3、V2O5、
Bi2O3、PbOの一種あるいは二種以上を任意の割
合で混合したものでもよい。この低融点酸化物
は、感湿抵抗素子を水分以外のガスに対して不活
性とする役目を有している。感湿抵抗素子中の該
低融点酸化物の含有量は、0.5〜２モル％である
ことが望ましい。２モル％以上になると雑ガスの
みならず、水分に対しても活性が低下し、感湿抵
抗素子の感湿感度が低下する。逆に、0.5モル％
以下では、雑ガスに対しても電気抵抗値が変化す
るようになり、該低融点酸化物の添加効果が現わ
れにくくなる。
該低融点酸化物は、上記複合酸化物を覆うよう
に存在する。それ故該感湿抵抗素子は、これを取
りまく大気中の相対湿度によつて電気抵抗値が変
化するとともに、低融点酸化物を含んでいるため
に、水分以外の雑ガスによる感度低下が抑制され
るという優れた性能を有する。
すなわち、従来のように、感度が低下した場合
に行なう加熱等によるクリーニングも不要となる
ので、クリーニング用ヒータおよび制御回路を必
要としない。
本発明にかかる感湿抵抗素子は、たとえば次の
ようにして製作することができる。まず、複合酸
化物を得るために、所望の金属酸化物、水酸化物
あるいは金属の炭酸塩、硝酸塩等、加熱すること
によつて酸化物となる塩を原料とし、所望の量、
秤量して混合し、必要であればボールミル等で粉
砕する。得られる混合粉末を800〜1000℃で仮焼
成し、スピネル構造を主体とする複合酸化物とす
る。
一方、低融点酸化物の粉末を用意し、上記複合
酸化物と混合、粉砕し、粉末の原料を得る。粉末
の粒径は0.1〜1μｍの範囲が、感湿抵抗素子の感
度、耐久性等から見て望ましい。該混合粉末を、
必要であればポリビニールアルコール等の粘結剤
を加えて混練し、30Kg／cm2〜2ton／cm2の圧力で、
円板状等の所望形状に加圧し、成形体とする。さ
らに、該成形体を電気炉等により、650゜〜1100℃
で１〜２時間焼成し、本発明にかかる感湿抵抗素
子を得る。焼成温度は、混合した低融点酸化物の
融点以上沸点以下の温度である。以上のようにし
て、本発明にかかる感湿抵抗素子を製作すること
ができる。
該感湿抵抗素子の表面に酸化ルテニウムの電
極、さらにその上に銀皮膜を形成したのち、リー
ド線をハンダ付けしてもよい。
以下、本発明の実施例を説明する。
まず、表の各実施例番号１〜16、と比較例とし
てのC1、C2に示す組成となるように、ZnO、
MgCO3、Na2CO3、KNO3、Li2CO3、Fe2O3のう
ちの該当するものを組合せて、複合酸化物用原料
を得る。この原料を乳鉢で混合、粉砕したのち、
約50Kg／cm2の圧力で直径11mmの円板に粗成形し、
800〜1100℃の温度で２時記大気雰囲気の加熱を
行ない、仮焼成体18種を得た。各仮焼成体を再び
乳鉢、乳棒で粉砕して粉末とし、さらに各粉末に
各実施番号に示した低融点酸化物を粉末状態で加
え、再混合、粉砕した。次に、これらの粉末を圧
力1ton／cm2で直径11mm、厚さ１mmの円板状体に成
形し、表に示した焼成温度、時間で本焼成した。
以上のようにして本発明にかかる16種の感湿抵抗
素子と、比較用としての２種の感湿抵抗素子を製
作した。
The present invention relates to a humidity-sensitive resistance element that is made of a sintered body of metal oxide, is capable of detecting changes in relative humidity as changes in electrical resistance, and is resistant to deterioration of detection ability due to miscellaneous gases in the air. . Generally, the sensing part of a moisture-sensitive resistance element is made of organic polymer such as polyamide resin or polyethylene, or
Metal oxides such as Fe 2 O 3 and Cr 2 O 3 are used.
However, metal oxides are chemically and physically relatively more stable than organic polymers, and are therefore promising as materials for moisture-sensitive resistance elements. However, ordinary metal oxides have drawbacks such as high specific resistance, small resistance change due to humidity changes, and hysteresis in the humidity-resistance characteristics under humidification-dehumidification conditions. Therefore, it was not suitable as a material for a moisture-sensitive resistance element. Therefore, the inventors developed a humidity-sensitive material that has low resistance, whose value changes by two to three orders of magnitude against relative humidity of 0 to 100%, and whose characteristics do not change over a long period of time even in high-temperature and high-humidity environments. As a material for a resistance element, M 1-x AxFe 2 O 4- 〓 system {where M: magnesium (Mg) or zinc (Zn), A: alkali metal, that is, lithium (Li), sodium (Na), or Potassium (k),
We discovered a fired material of Fe (iron), manufactured an excellent moisture-sensitive resistance element using this material, and filed an application (Japanese Patent Application No. 56-196534). This element has the feature that characteristic fluctuations are extremely small even if it is used for more than one year in a relatively clean room. However, when exposed to air contaminated with gases other than moisture, such as cigarette smoke, the electrical resistance of the element increases, causing discrepancies with the initial characteristics. This discrepancy in characteristics disappears if the device is heated to a temperature above about 400°C for several minutes. However, in devices that frequently require heat treatment during use, it is necessary to incorporate a heater and a control circuit into the device, resulting in problems such as a complicated structure of the device itself. Therefore, the inventors discovered that by adding a metal oxide with a low melting point to the M 1-x AxFe 2 O 4- 〓-based substance, this substance becomes inactive against miscellaneous gases other than moisture, such as cigarette smoke. Based on this discovery, we have completed a moisture-sensitive resistance element that overcomes the above-mentioned conventional problems. That is,
The present invention is based on M 1-x AxFe 2 O 4- {where M is magnesium (Mg) or zinc (Zn), A is an alkali metal,
0.001<x<0.2, α is the number of oxygen vacancies, Fe is iron, O
is a complex oxide represented by oxygen}, and at least one selected from boron oxide (B 2 O 3 ), bismuth oxide (Bi 2 O 3 ), vanadium oxide (V 2 O 5 ), and lead oxide (PbO). This is a moisture-sensitive resistance element characterized by comprising a low melting point oxide. The humidity-sensitive resistance element according to the present invention has a large electrical resistance change with respect to a change in relative humidity, and has little hysteresis in its characteristics.In addition, since a very small amount of low-melting point oxide is present, cigarette smoke etc. It has an excellent property of less deterioration of characteristics due to miscellaneous gases. The present invention will be explained in more detail below. The moisture sensitive resistance element according to the present invention is made of a composite oxide and a low melting point oxide. The above composite oxide has M of 0.1 to 20 in MFe 2 O 4 which is spinel.
It has a form in which % of atoms are replaced with an alkali metal, and is expressed by the general formula "M 1-x AxFe 2 O 4- ". Here, the value of x is in the range of 0.001 to 0.2, and good moisture sensitivity characteristics are exhibited within this range.
Furthermore, in the range of 0.01 to 0.05, the relationship between the relative humidity and the logarithm of the electrical resistance value becomes almost linearly proportional, making the humidity-sensitive resistance element easier to use. Also,
α is a value determined by the amount of alkali metal,
Its value is approximately x/2. On the other hand, the low melting point oxides include B 2 O 3 , V 2 O 5 ,
One or more of Bi 2 O 3 and PbO may be mixed in any proportion. This low melting point oxide has the role of making the humidity sensitive resistance element inert to gases other than moisture. The content of the low melting point oxide in the moisture sensitive resistance element is preferably 0.5 to 2 mol%. If it exceeds 2 mol %, the activity against not only miscellaneous gases but also moisture decreases, resulting in a decrease in the humidity sensitivity of the humidity-sensitive resistance element. Conversely, 0.5 mol%
Below, the electrical resistance value also changes with respect to miscellaneous gases, and the effect of adding the low melting point oxide becomes less apparent. The low melting point oxide is present so as to cover the composite oxide. Therefore, the electrical resistance value of the humidity-sensitive resistance element changes depending on the relative humidity of the surrounding atmosphere, and since it contains a low-melting-point oxide, a decrease in sensitivity due to miscellaneous gases other than moisture is suppressed. It has excellent performance. That is, cleaning by heating or the like, which is performed when the sensitivity decreases, as in the prior art, is not required, and therefore a cleaning heater and a control circuit are not required. The moisture-sensitive resistance element according to the present invention can be manufactured, for example, as follows. First, in order to obtain a composite oxide, a desired metal oxide, hydroxide, or metal carbonate, nitrate, or other salt that becomes an oxide by heating is used as a raw material, and the desired amount of
Weigh and mix, and if necessary, grind with a ball mill or the like. The obtained mixed powder is calcined at 800 to 1000°C to form a composite oxide mainly having a spinel structure. On the other hand, a powder of a low melting point oxide is prepared, mixed with the above composite oxide, and pulverized to obtain a raw material for the powder. The particle size of the powder is preferably in the range of 0.1 to 1 μm in view of the sensitivity, durability, etc. of the moisture-sensitive resistance element. The mixed powder,
If necessary, add a binder such as polyvinyl alcohol and knead, then apply a pressure of 30Kg/ cm2 to 2ton/ cm2 .
It is pressurized into a desired shape such as a disk shape to form a molded body. Furthermore, the molded body is heated to 650° to 1100°C in an electric furnace or the like.
The sample is baked for 1 to 2 hours to obtain a moisture-sensitive resistance element according to the present invention. The firing temperature is a temperature above the melting point and below the boiling point of the mixed low melting point oxide. In the manner described above, the moisture-sensitive resistance element according to the present invention can be manufactured. After forming a ruthenium oxide electrode on the surface of the humidity-sensitive resistance element and further forming a silver film thereon, lead wires may be soldered. Examples of the present invention will be described below. First, ZnO,
A raw material for a composite oxide is obtained by combining appropriate ones of MgCO 3 , Na 2 CO 3 , KNO 3 , Li 2 CO 3 , and Fe 2 O 3 . After mixing and crushing these raw materials in a mortar,
Roughly formed into a disc with a diameter of 11 mm at a pressure of approximately 50 kg/cm 2 ,
Heating was carried out in an atmospheric atmosphere for 2 hours at a temperature of 800 to 1100°C to obtain 18 types of pre-fired bodies. Each calcined body was again crushed into powder using a mortar and pestle, and the low melting point oxide indicated by each execution number was added in powder form to each powder, and the mixture was remixed and crushed. Next, these powders were molded into a disc-shaped body with a diameter of 11 mm and a thickness of 1 mm at a pressure of 1 ton/cm 2 , and main firing was performed at the firing temperature and time shown in the table.
As described above, 16 types of humidity-sensitive resistance elements according to the present invention and two types of humidity-sensitive resistance elements for comparison were manufactured.
【表】
その後、上記感湿抵抗素子の両面を研摩したの
ち、アセトンで洗浄し、該素子の両面に酸化ルテ
ニウム（RuO2）ペーストを直径10mmの円形状に
塗布し、大気雰囲気で800℃に加熱し、電極を焼
付けた。さらに、この電極の一部表面に銀ペース
トをつけて700℃に加熱することにより、銀の面
を形成し、そこに、リード線を半円付けした。
上記感湿抵抗素子の感湿特性を調査するため
に、まず、これらの素子を恒温恒湿槽に入れ、槽
内の温度を25℃一定にしたままで、相対湿度を０
〜100％の範囲内で変化させた。このときの相対
湿度と素子の電気抵抗との関係を求めた。素子の
電気抵抗は交流ブリツジ（周波数1KHz）により
測定した。電気抵抗値の対数と相対湿度との間に
はほぼ直線の関係が見られる。これらの関係の代
表例を第１図に示す。曲線につけた番号は表に示
した実施番号の素子に対応する。
次に、上記素子の煙草の煙による感湿特性の劣
化の程度を調べるために、内容積250c.c.の容器内
に巻たばこを１本入れて燃焼させ、さらに上記素
子を投入して24時間放置した。この試験のあと、
相対湿度−電気抵抗の関係を求めた。上記、試験
を３回繰返したあとの感湿特性には、実施番号１
〜16のものでは初期特性から10％以下の偏倚しか
現れなかつたが、C1およびC2比較例においては
20％以上の偏倚を示した。第２図には、実施番号
３とC1の場合について、初期特性（実線）と、
煙による試験を３回実施したのちの特性（破線）
とを比較して示す。第３図には、実施番号３と
C1の場合について、たばこ試験の回数による特
性変化の様子を、相対湿度90％、60％、30％にお
いて測定した抵抗値で示す。これらの図からわか
るように、本発明にかかる感湿抵抗素子は、たば
こ試験の回数にかかわらず抵抗値の変化は極く少
ないが、比較例のものでは、試験回数の増加とと
もに抵抗値が増加する。すなわち比較例の素子は
煙に晒されると、感湿特性が低下するが、本願に
かかる素子の感湿特性はほとんど変化しないこと
がわかる。また、低融点酸化物を添加することに
よつて、低湿度雰囲気中での電気抵抗値が若干低
下するので、感湿感度は若干低下するが使用しや
すい感湿抵抗素子となる。さらに、低融点酸化物
によつて、複合酸化物が結合された構造となるの
で、機械的強度が向上し、取扱いやすくなる等の
効果も得られた。[Table] After that, both sides of the moisture-sensitive resistance element were polished, washed with acetone, and ruthenium oxide (RuO 2 ) paste was applied to both sides of the element in a circular shape with a diameter of 10 mm, and heated to 800°C in an air atmosphere. The electrode was baked by heating. Furthermore, silver paste was applied to a portion of the surface of this electrode and heated to 700°C to form a silver surface, to which a semicircular lead wire was attached. In order to investigate the humidity-sensitive characteristics of the above-mentioned humidity-sensitive resistance elements, first, these elements were placed in a constant temperature and humidity chamber, and the relative humidity was set to 0 while keeping the temperature in the chamber constant at 25°C.
It was varied within the range of ~100%. The relationship between the relative humidity and the electrical resistance of the element at this time was determined. The electrical resistance of the element was measured using an AC bridge (frequency 1KHz). A nearly linear relationship can be seen between the logarithm of electrical resistance and relative humidity. A typical example of these relationships is shown in FIG. The numbers on the curves correspond to the elements with implementation numbers shown in the table. Next, in order to examine the degree of deterioration of the moisture sensitivity characteristics of the above element due to cigarette smoke, one rolled cigarette was placed in a container with an internal volume of 250 c.c. and burned, and the above element was further placed in the container. I left it for a while. After this test,
The relationship between relative humidity and electrical resistance was determined. The moisture sensitivity characteristics after repeating the above test three times are as follows:
~16 showed a deviation of less than 10% from the initial characteristics, but in the C1 and C2 comparative examples,
It showed a deviation of more than 20%. Figure 2 shows the initial characteristics (solid line) and the case of implementation number 3 and C1.
Characteristics after three smoke tests (dashed line)
A comparison is shown below. Figure 3 shows implementation number 3 and
For C1, the change in characteristics due to the number of tobacco tests is shown by the resistance values measured at relative humidity of 90%, 60%, and 30%. As can be seen from these figures, the resistance value of the moisture-sensitive resistance element according to the present invention shows very little change regardless of the number of tobacco tests, but the resistance value of the comparative example increases as the number of tests increases. do. That is, it can be seen that when the element of the comparative example is exposed to smoke, the moisture sensitivity characteristics deteriorate, but the moisture sensitivity characteristics of the element according to the present application hardly change. Furthermore, by adding a low melting point oxide, the electrical resistance value in a low humidity atmosphere is slightly lowered, resulting in a humidity-sensitive resistance element that is easy to use, although the humidity sensitivity is slightly lowered. Furthermore, since the composite oxide is bonded by the low melting point oxide, mechanical strength is improved and handling becomes easier.
第１〜３図は実施例を示す図であり、第１図は
感湿抵抗素子の相対湿度−電気抵抗特性の代表例
を示す線図、第２図は煙による試験の前後におけ
る相対湿度−電気抵抗特性の代表例を示す線図、
第３図は、たばこ試験の回数と電気抵抗値との関
係の代表例を示す線図である。
Figures 1 to 3 are diagrams showing examples; Figure 1 is a diagram showing a typical example of the relative humidity-electrical resistance characteristics of a humidity-sensitive resistance element; Figure 2 is a diagram showing the relative humidity before and after the smoke test; Diagram showing typical examples of electrical resistance characteristics,
FIG. 3 is a diagram showing a typical example of the relationship between the number of tobacco tests and the electrical resistance value.
Claims (1)
は亜鉛、Ａはアルカリ金属、0.001＜ｘ＜0.2、α
は酸素空格子数）により表わされる複合酸化物
と、酸化ホウ素、酸化ビヒマス、酸化バナジウム
および酸化鉛のうちから少なくとも一種選ばれた
低融点酸化物とからなることを特徴とする感湿抵
抗素子。 ２ 上記低融点酸化物は0.5〜２モル％含まれて
いることを特徴とする特許請求の範囲第１項記載
の感湿抵抗素子。[Claims] 1 M 1-x AxFe 2 O 4- (where M is magnesium or zinc, A is an alkali metal, 0.001<x<0.2, α
1. A moisture-sensitive resistance element comprising a composite oxide represented by the number of oxygen vacancies) and a low-melting-point oxide selected from at least one of boron oxide, bihumuth oxide, vanadium oxide, and lead oxide. 2. The moisture-sensitive resistance element according to claim 1, wherein the low melting point oxide is contained in an amount of 0.5 to 2 mol%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59014739A JPS60160102A (en) | 1984-01-30 | 1984-01-30 | moisture sensitive resistance element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59014739A JPS60160102A (en) | 1984-01-30 | 1984-01-30 | moisture sensitive resistance element |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60160102A JPS60160102A (en) | 1985-08-21 |
| JPH0318721B2 true JPH0318721B2 (en) | 1991-03-13 |
Family
ID=11869485
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59014739A Granted JPS60160102A (en) | 1984-01-30 | 1984-01-30 | moisture sensitive resistance element |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60160102A (en) |
-
1984
- 1984-01-30 JP JP59014739A patent/JPS60160102A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60160102A (en) | 1985-08-21 |
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