JP5335288B2 - Glass electrode and its response glass - Google Patents
Glass electrode and its response glass Download PDFInfo
- Publication number
- JP5335288B2 JP5335288B2 JP2008141899A JP2008141899A JP5335288B2 JP 5335288 B2 JP5335288 B2 JP 5335288B2 JP 2008141899 A JP2008141899 A JP 2008141899A JP 2008141899 A JP2008141899 A JP 2008141899A JP 5335288 B2 JP5335288 B2 JP 5335288B2
- Authority
- JP
- Japan
- Prior art keywords
- glass
- response
- electrode
- responsive
- alkali
- 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.)
- Active
Links
- 239000011521 glass Substances 0.000 title claims description 79
- 230000004044 response Effects 0.000 title claims description 50
- 239000003513 alkali Substances 0.000 claims description 30
- 229910021193 La 2 O 3 Inorganic materials 0.000 claims description 17
- 229910052747 lanthanoid Inorganic materials 0.000 claims description 17
- 150000002602 lanthanoids Chemical class 0.000 claims description 17
- 238000006386 neutralization reaction Methods 0.000 claims description 12
- 239000000203 mixture Substances 0.000 claims description 5
- 238000010998 test method Methods 0.000 claims description 3
- 239000006123 lithium glass Substances 0.000 claims description 2
- 239000002904 solvent Substances 0.000 claims description 2
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 9
- 229910052706 scandium Inorganic materials 0.000 description 8
- 229910052727 yttrium Inorganic materials 0.000 description 8
- 230000004043 responsiveness Effects 0.000 description 7
- 230000035945 sensitivity Effects 0.000 description 6
- 238000004031 devitrification Methods 0.000 description 5
- 239000000243 solution Substances 0.000 description 5
- 238000012360 testing method Methods 0.000 description 5
- 229910052779 Neodymium Inorganic materials 0.000 description 4
- WCUXLLCKKVVCTQ-UHFFFAOYSA-M Potassium chloride Chemical compound [Cl-].[K+] WCUXLLCKKVVCTQ-UHFFFAOYSA-M 0.000 description 4
- 239000002131 composite material Substances 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 229910052691 Erbium Inorganic materials 0.000 description 3
- 229910052688 Gadolinium Inorganic materials 0.000 description 3
- 229910052769 Ytterbium Inorganic materials 0.000 description 3
- 239000002253 acid Substances 0.000 description 3
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 230000036571 hydration Effects 0.000 description 3
- 238000006703 hydration reaction Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 229910052760 oxygen Inorganic materials 0.000 description 3
- 239000001301 oxygen Substances 0.000 description 3
- 238000004448 titration Methods 0.000 description 3
- 238000000954 titration curve Methods 0.000 description 3
- 229910018068 Li 2 O Inorganic materials 0.000 description 2
- 229910017493 Nd 2 O 3 Inorganic materials 0.000 description 2
- 229910004298 SiO 2 Inorganic materials 0.000 description 2
- 239000003125 aqueous solvent Substances 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 239000010705 motor oil Substances 0.000 description 2
- 239000001103 potassium chloride Substances 0.000 description 2
- 235000011164 potassium chloride Nutrition 0.000 description 2
- 238000003918 potentiometric titration Methods 0.000 description 2
- 239000008399 tap water Substances 0.000 description 2
- 235000020679 tap water Nutrition 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910052684 Cerium Inorganic materials 0.000 description 1
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- 239000012670 alkaline solution Substances 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- PAZHGORSDKKUPI-UHFFFAOYSA-N lithium metasilicate Chemical compound [Li+].[Li+].[O-][Si]([O-])=O PAZHGORSDKKUPI-UHFFFAOYSA-N 0.000 description 1
- 229910052912 lithium silicate Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000003209 petroleum derivative Substances 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 239000005368 silicate glass Substances 0.000 description 1
Landscapes
- Glass Compositions (AREA)
Description
本発明はｐＨ応答性のガラス電極に関し、特にその応答ガラスの組成に関するものである。 The present invention relates to a pH-responsive glass electrode, and more particularly to the composition of the responsive glass.
例えばｐＨ電極等に用いられるＳｉＯ２系、Ｌｉ２Ｏ系の応答ガラスでは、アルカリ誤差、酸誤差が小さいこと、応答性がよいこと、化学的耐久性がよいこと等の諸性質が要求される（この他に、電位勾配が理論値に近いこと、電気抵抗が少ないこと、機械的強度が大きいこと、加工が容易であること等も要求性質として挙げられる）。 For example, SiO 2 -based and Li 2 O-based response glasses used for pH electrodes and the like require various properties such as low alkali error, acid error, good response, and good chemical durability. (In addition to this, the required properties include that the potential gradient is close to the theoretical value, the electrical resistance is small, the mechanical strength is large, and the processing is easy).
これら諸性質の向上を図るために、３価金属であるＬａを少量ガラス組成に含有させて、アルカリ誤差を惹起させにくくしたものが知られている（非特許文献１）。 In order to improve these various properties, it is known that a small amount of La, which is a trivalent metal, is contained in a glass composition to make it difficult to cause an alkali error (Non-Patent Document 1).
Ｌａ及び他のランタノイド（Ｎｄ、Ｇｄ、Ｅｒ、Ｙｂ等）は、３価であり、酸素４配位により形成される１価アニオンの静電力が小さくなるため、アルカリ金属に応答しにくい、すなわちアルカリ誤差を惹起させにくく（低アルカリ誤差）、またアルカリへの溶解度が低い。その効果は、イオン半径の大きさ（Ｌａ＞Ｎｄ＞Ｇｄ＞Ｅｒ＞Ｙｂ）に比例し、最もイオン半径が大きいＬａが、最も耐アルカリ性に優れ、低アルカリ誤差の性質を持つ。 La and other lanthanoids (Nd, Gd, Er, Yb, etc.) are trivalent, and since the electrostatic force of monovalent anions formed by oxygen tetracoordination is small, it is difficult to respond to alkali metals, Difficult to cause errors (low alkali error) and low solubility in alkali. The effect is proportional to the size of the ionic radius (La> Nd> Gd> Er> Yb), and La having the largest ionic radius has the highest alkali resistance and has the property of low alkali error.
しかしながら、Ｌａを添加しても、Ｌａはイオン半径が大きいことから、比較的電子親和力が弱く、酸素との結合力が弱いため、得られた応答ガラスの化学的耐久性や応答性は、実用的には未だ不充分である。また、Ｌａは水和層の引き締め力が比較的弱く、水和層が厚くなるため、応答性向上にも限界がある。 However, even if La is added, since La has a large ionic radius, its electron affinity is relatively weak and its binding force with oxygen is weak. Therefore, the chemical durability and responsiveness of the obtained response glass are practical. Is still inadequate. In addition, La has a relatively weak tightening force in the hydrated layer, and the hydrated layer becomes thick. Therefore, there is a limit to improving the response.
そこで、本発明者は、Ｌａに加えて、Ｌａよりもイオン半径が小さい３族金属あるＹやＳｃを並存させることにより、応答ガラスの耐酸性や耐水性又は応答性を、他の諸性質（特に低アルカリ誤差）を劣化させることなく、向上させることを達成した（特許文献１）。
しかしながら、Ｌａは他のランタノイドよりガラスへの溶融度が低く、このためＬａを含有するガラスは、その融液を冷却固化する際に、ガラス中に結晶が析出して失透しやすく、失透したガラスは物理的性質が変化し軟化しにくくなるので、作業性や加工性が低下するという問題を有する。特に、破損しにくくするために厚みのある応答ガラス（以下、タフ応答ガラスともいう。）に成形した場合は、冷却に時間がかかるので、失透しやすい。 However, La has a lower degree of melting into glass than other lanthanoids. Therefore, when La contains glass, when the melt is cooled and solidified, crystals are likely to precipitate in the glass and devitrify. However, the glass has a problem that workability and workability deteriorate because the physical properties change and it is difficult to soften. In particular, when it is formed into a thick response glass (hereinafter also referred to as tough response glass) in order to make it difficult to break, it takes time to cool down, and thus it tends to devitrify.
このように失透したタフ応答ガラスを、支持ガラス管と接合させようとすると、接合部が融着しなくなり、支持管との接合ができなくなるという問題が生じる。 If the tough responsive glass devitrified as described above is to be bonded to the support glass tube, there is a problem that the bonded portion is not fused and cannot be bonded to the support tube.
そこで本発明は、耐久性、応答性、耐アルカリ性、低アルカリ誤差等の諸性質に優れ、かつ、失透も起こりにくい応答ガラスを提供すべく図ったものである。 Therefore, the present invention is intended to provide a response glass that is excellent in various properties such as durability, responsiveness, alkali resistance, and low alkali error, and hardly causes devitrification.
本発明者は、鋭意検討の結果、Ｌａの一部を、Ｌａよりもイオン半径が小さくガラスへの溶融度が高く、かつ、ＹやＳｃよりもイオン半径が大きいために耐アルカリ性に優れ、低アルカリ誤差の性質を持つ他のランタノイドに置き換えた上で、ＹやＳｃと並存させることにより、応答ガラスとしての優れた諸性質を維持したまま、前記のような失透を防ぐことができることを見出し、この知見に基づき本発明を完成させた。 As a result of intensive studies, the inventor has found that a part of La has an excellent alkali resistance and a low ionic radius because it has a smaller ionic radius than La and a high degree of melting into glass, and a larger ionic radius than Y and Sc. After replacing with other lanthanoids having the property of alkali error, it was found that the above-mentioned devitrification can be prevented while maintaining excellent properties as a response glass by coexisting with Y and Sc. Based on this finding, the present invention has been completed.
すなわち、本発明に係るｐＨ応答性ガラス電極は、その応答ガラスの成分組成として、少なくともＬａ2Ｏ３及びＭｅ2Ｏ３（ＭｅはＬａ以外のランタノイド）を含み、その他にＬａ2Ｏ３及びＭｅ2Ｏ３の合計量よりも少量のＹ２Ｏ３又はＳｃ２Ｏ３を含むことを特徴とするものである。なお、ここで「少量」とは、モル換算して比較した場合をいうものである。 That is, the pH-responsive glass electrode according to the present invention contains at least La 2 O 3 and Me 2 O 3 (Me is a lanthanoid other than La) as a component composition of the response glass, and La 2 O 3 and Me. than the total amount of 2 O 3 is characterized in that a small amount of Y 2 O 3 or Sc 2 O 3. Here, “small amount” refers to a case where a comparison is made in terms of mole.
かかる本発明によれば、応答ガラスの耐久性、応答性、耐アルカリ性、低アルカリ誤差等の諸性質に優れ、かつ、失透も起こりにくい応答ガラスを得ることができる。 According to the present invention, it is possible to obtain a response glass that is excellent in various properties such as durability, responsiveness, alkali resistance, and low alkali error of the response glass, and that hardly causes devitrification.
応答性向上の理由としては、ＹやＳｃは、電子親和力が強いことから酸素との結合力が強く、少量でも水和ゲル層を引き締めてその厚みを薄くするので、プロトンの拡散通過時間が短縮されて、応答性向上を大きく促進させるからであると考えられる。そしてこの応答性向上により、例えば従来どおり測定対象液に浸々させて一定時間後に自動校正した場合に、そのときの出力電圧は従来品に比べより安定した状態にあるので、自動校正を再現性よくかつ正確に行うことができ、結果として測定時の再現性や感度が向上することになる。 The reason for improving the response is that Y and Sc have a strong electron affinity and thus have a strong binding force with oxygen. Even in small amounts, the hydrated gel layer is tightened to reduce its thickness, so that the proton diffusion time is shortened. It is thought that this is because the improvement of responsiveness is greatly promoted. With this improved response, for example, when the sample is immersed in the solution to be measured and automatically calibrated after a certain period of time, the output voltage at that time is more stable than that of the conventional product. This can be performed well and accurately, and as a result, reproducibility and sensitivity during measurement are improved.
化学的耐久性向上の理由としては、ＹやＳｃは、Ｌａ及び他のランタノイドに比べ、イオン半径が小さく電子親和力が強いため、少量でもガラスの網目構造内に充填されると、他のカチオン（Ｌｉ+、Ｈ３Ｏ+等）を電気的に反発してそれらが水和ゲル層を通過することを抑制し、化学的耐久性を大きく向上させるからであると考えられる。 The reason for the improvement in chemical durability is that Y and Sc have a smaller ionic radius and stronger electron affinity than La and other lanthanoids, so that even when a small amount is filled in the glass network structure, other cations ( Li + , H 3 O + and the like) are electrically repelled, and they are prevented from passing through the hydrated gel layer, and the chemical durability is greatly improved.
耐アルカリ性に優れている理由としては、ＹやＳｃに比べてＬａ及び他のランタノイドがアルカリへの溶解度が低いからであると考えられる。 It is considered that the reason why the alkali resistance is excellent is that La and other lanthanoids have lower solubility in alkali than Y or Sc.
低アルカリ誤差を担保できる理由としては、Ｌａ及び他のランタノイドに加えて、モル比においてそれより少量のＹまたはＳｃを応答ガラスに含有させるようにしているので、アルカリ誤差においてＬａ及び他のランタノイドの影響が支配的になり、Ｙ、Ｓｃのアルカリ誤差に及ぼす悪影響を抑制できるからであると考えられる。 The reason why the low alkali error can be secured is that, in addition to La and other lanthanoids, a smaller amount of Y or Sc in a molar ratio is contained in the response glass. This is considered to be because the influence becomes dominant and the adverse effect on the alkali error of Y and Sc can be suppressed.
前記作用効果を特に顕著に発揮させるためには、Ｙ２Ｏ３又はＳｃ２Ｏ３のＬａ2Ｏ３及びＭｅ2Ｏ３の合計量に対するモル比が１／２〜１／３０であることが好ましい。応答ガラス全体に対する分量で言えば、Ｌａ2Ｏ３及びＭｅ2Ｏ３が合わせて４〜６ｍｏｌ％含まれていることが好ましく、Ｙ２Ｏ３又はＳｃ２Ｏ３が０．１ｍｏｌ％以上含まれていることが好ましい。また、前記応答ガラスの表面に形成される水和層の厚みを基準にして言えば、応答ガラスを水に浸々させて安定状態となった状態において、水和層の厚みが６０ｎｍ以下となるような、Ｙ２Ｏ３又はＳｃ２Ｏ３の含有量であることが好ましい。 In order to exhibit the above-mentioned effects particularly remarkably, the molar ratio of Y 2 O 3 or Sc 2 O 3 to the total amount of La 2 O 3 and Me 2 O 3 is 1/2 to 1/30. preferable. In terms of the amount of the entire response glass, La 2 O 3 and Me 2 O 3 are preferably contained in a total amount of 4 to 6 mol%, and Y 2 O 3 or Sc 2 O 3 is contained in an amount of 0.1 mol% or more. It is preferable. In addition, in terms of the thickness of the hydrated layer formed on the surface of the response glass, the thickness of the hydrated layer becomes 60 nm or less in a state where the response glass is immersed in water and becomes stable. Such a content of Y 2 O 3 or Sc 2 O 3 is preferable.
前記Ｍｅとしては特に限定されず、Ｌａ以外のランタノイドであればよく、例えば、Ｎｄ、Ｇｄ、Ｅｒ、Ｙｂ等が挙げられるが、なかでもＮｄが好ましい。ＭｅとしてＬａの次にイオン半径が大きいＮｄを用いると、耐アルカリ性に優れ、かつ、アルカリ誤差が惹起されにくい応答ガラスを得ることができる。 The Me is not particularly limited, and may be any lanthanoid other than La, and examples thereof include Nd, Gd, Er, Yb, etc. Among them, Nd is preferable. When Nd having the next largest ion radius after La is used as Me, it is possible to obtain a response glass which is excellent in alkali resistance and hardly causes an alkali error.
前記応答ガラスは、リチウム系ガラスが好ましい。 The response glass is preferably a lithium glass.
本発明に係るｐＨ応答性ガラス電極の用途としては特に限定されないが、例えば、非水溶媒用の電極として好適に用いることができる。従来のｐＨガラス電極は、非水溶媒中で水和層が形成されにくく、応答が遅かったため、石油製品の中和価試験方法等に用いた場合は中和点を測定することが困難であったが、本発明に係るｐＨ応答性ガラス電極は水和層が薄く応答速度が速いので、非水溶媒用の電極として用いて、石油製品の中和価試験方法等に供した場合、中和価の迅速かつ精度の高い測定を可能とする。 Although it does not specifically limit as a use of the pH responsive glass electrode which concerns on this invention, For example, it can use suitably as an electrode for nonaqueous solvents. In the conventional pH glass electrode, a hydrated layer is difficult to form in a non-aqueous solvent and the response is slow. Therefore, it was difficult to measure the neutralization point when used in a method for testing the neutralization value of petroleum products. However, since the pH-responsive glass electrode according to the present invention has a thin hydration layer and a high response speed, it is used as an electrode for a non-aqueous solvent. Enables quick and accurate measurement of the price.
本発明に係る中和価試験方法は、本発明に係るｐＨ応答性ガラス電極を使用する方法であれば特に限定されず、例えば、ＪＩＳ Ｋ ２５０１に規格化されている電位差滴定法に準拠する方法等が挙げられる。 The neutralization number test method according to the present invention is not particularly limited as long as it uses the pH-responsive glass electrode according to the present invention. For example, a method based on a potentiometric titration standardized in JIS K 2501. Etc.
本発明に係るｐＨ応答性ガラス電極の用途としては、他に、アルカリ性環境下においても諸性質が維持されることから、耐アルカリ用電極としてアルカリ性溶液のｐＨを測定する場合等に好適に用いることができる。 As other uses of the pH-responsive glass electrode according to the present invention, other properties are maintained even in an alkaline environment. Therefore, the pH-responsive glass electrode is preferably used when measuring the pH of an alkaline solution as an alkali-resistant electrode. Can do.
このような構成の本発明によれば、耐久性、応答性、耐アルカリ性、低アルカリ誤差等の諸性質に優れ、かつ、失透も起こりにくい応答ガラスを提供することができる。 According to the present invention having such a configuration, it is possible to provide a response glass which is excellent in various properties such as durability, responsiveness, alkali resistance, low alkali error and the like and hardly causes devitrification.
以下に本発明の一実施形態について説明する。 Hereinafter, an embodiment of the present invention will be described.
この実施形態に係るｐＨ応答性ガラス電極１は、例えば図１に示すように、内部電極２、比較電極３を一体に有する複合型のものである。この図１において符号４は支持ガラス管、符号５は応答ガラス、符号６は液絡部を示している。また、支持ガラス管４内部には一定濃度の塩化カリウム溶液が充填してあり、内部電極２及び比較電極３がその塩化カリウム溶液に浸されるように構成している。 The pH-responsive glass electrode 1 according to this embodiment is a composite type having an internal electrode 2 and a comparison electrode 3 as shown in FIG. In FIG. 1, reference numeral 4 indicates a supporting glass tube, reference numeral 5 indicates response glass, and reference numeral 6 indicates a liquid junction. The supporting glass tube 4 is filled with a potassium chloride solution having a constant concentration, and the internal electrode 2 and the comparative electrode 3 are soaked in the potassium chloride solution.
しかしてこの応答ガラス５は、底面５１から側面５２にいたるまで、ＳｉＯ２を主成分（５０〜７０ｍｏｌ％）、Ｌｉ２Ｏを副成分（１０〜３０ｍｏｌ％）とし、その他に種々の修飾金属（あわせて約１０ｍｏｌ％）を含むものである。そして、この実施形態では、修飾金属として少なくともＬａ2Ｏ３及びＭｅ2Ｏ３（ＭｅはＬａ以外のランタノイド）を含み、その他にＬａ2Ｏ３及びＭｅ2Ｏ３の合計量よりも少量のＹ２Ｏ３又はＳｃ２Ｏ３を含むように構成している。 The response glass 5 is composed of, from the bottom surface 51 to the side surface 52, SiO 2 as a main component (50 to 70 mol%), Li 2 O as a subcomponent (10 to 30 mol%), and various other modified metals ( And about 10 mol%). In this embodiment, the modified metal contains at least La 2 O 3 and Me 2 O 3 (Me is a lanthanoid other than La), and in addition, Y is smaller than the total amount of La 2 O 3 and Me 2 O 3. 2 O 3 or Sc 2 O 3 is included.
ＭｅとはＬａ以外のランタノイド（Ｎｄ、Ｇｄ、Ｅｒ、Ｙｂ、Ｃｅ等）であればよいが、好ましくは、Ｎｄである。また応答ガラス全体に占めるＬａ2Ｏ３及びＭｅ2Ｏ３の合計の含有量は、４〜６ｍｏｌ％程度が好ましく、電気抵抗の上昇を考慮するとその上限は約１０ｍｏｌ％と考えられる。 Me may be any lanthanoid other than La (Nd, Gd, Er, Yb, Ce, etc.), but is preferably Nd. Further, the total content of La 2 O 3 and Me 2 O 3 in the entire response glass is preferably about 4 to 6 mol%, and the upper limit is considered to be about 10 mol% in consideration of an increase in electric resistance.
Ｙ２Ｏ３又はＳｃ２Ｏ３の、Ｌａ2Ｏ３及びＭｅ2Ｏ３の合計に対する含有量は、これが多すぎるとアルカリ誤差が実用範囲（例えばＪＩＳ規格）を超えてしまうし、少なすぎると応答特性を発揮できないことから、その範囲が定まる。応答特性を決めるパラメータとしては、水に浸したときに形成される表面水和層の厚みが挙げられる。前述したように、水和層が薄いほうが、プロトンの水和層通過時間が短縮されて、応答性が向上すると考えられるからである。Ｙ２Ｏ３又はＳｃ２Ｏ３の含有下限値は、その水和層の厚みが約６０ｎｍ以下となるように定めるのが非常に好ましい。Ｙ２Ｏ３又はＳｃ２Ｏ３の、Ｌａ2Ｏ３及びＭｅ2Ｏ３の合計に対する含有量（モル比）で言えば、約１／３０〜１／２であることが好ましく、より好ましくは約１／６〜約１／３がよい。 If the content of Y 2 O 3 or Sc 2 O 3 with respect to the total of La 2 O 3 and Me 2 O 3 is too large, the alkali error will exceed the practical range (for example, JIS standard), and if the content is too small. Since the response characteristics cannot be exhibited, the range is determined. The parameter that determines the response characteristics includes the thickness of the surface hydrated layer formed when immersed in water. This is because, as described above, it is considered that the thinner the hydration layer, the shorter the hydration layer passage time of protons, the better the responsiveness. The content lower limit value of Y 2 O 3 or Sc 2 O 3 is very preferably determined so that the thickness of the hydrated layer is about 60 nm or less. In terms of the content (molar ratio) of Y 2 O 3 or Sc 2 O 3 to the total of La 2 O 3 and Me 2 O 3 , it is preferably about 1/30 to 1/2, more preferably About 1/6 to about 1/3 is preferable.
なお、Ｙ２Ｏ３又はＳｃ２Ｏ３を含有させるとは、Ｙ２Ｏ３のみを含有させてもよいし、Ｓｃ２Ｏ３のみを含有させてもよいし、Ｙ２Ｏ３及びＳｃ２Ｏ３を混合して（この場合は２つのモル総量としてＭｅ２Ｏ３の約１／３０〜１／２程度になればよい）含有させてもよいという意味である。 Note that the to contain Y 2 O 3 or Sc 2 O 3, may be contained only Y 2 O 3, may be contained only Sc 2 O 3, Y 2 O 3 and Sc 2 This means that O 3 may be mixed and contained (in this case, the total amount of the two moles may be about 1/30 to 1/2 of Me 2 O 3 ).
Ｙ２Ｏ３又はＳｃ２Ｏ３の含有量としては、約０．１ｍｏｌ％以上であることが好ましく、性能面からだけ言えばその上限に特に制限はない。ただし、費用等の観点から約５ｍｏｌ％以下であることが好ましい。 Y The content of 2 O 3 or Sc 2 O 3, is preferably about 0.1 mol% or more, there is no particular limitation on the upper limit speaking only from performance. However, it is preferably about 5 mol% or less from the viewpoint of cost and the like.
また、応答ガラス５がＹ２Ｏ３を含んでいて、ＭｅがＮｄである場合は、Ｙ２Ｏ３の含有量が０．５〜５．５ｍｏｌ％、Ｌａ2Ｏ３の含有量が０．５〜５．５ｍｏｌ％、Ｎｄ2Ｏ３の含有量が０．５〜４ｍｏｌ％であって、Ｙ２Ｏ３、Ｌａ2Ｏ３及びＮｄ2Ｏ３の合計量が６〜８ｍｏｌ％であることが好ましい。この範囲を逸脱すると、応答ガラス５の耐久性、感度、応答性、耐アルカリ性、低アルカリ誤差等の諸性質が劣化し、実用に供することができなくなる場合がある。なお、応答ガラス５が厚みのある管状（タフ応答ガラス）である場合は、支持ガラス管４との溶融接合時に失透することを防ぐために、Ｌａ2Ｏ３の含有量を４ｍｏｌ％以下に抑えることが好ましい。 The response glass 5 comprise Y 2 O 3, when Me is Nd, Y 2 O 3 content is 0.5～5.5Mol%, the content of La 2 O 3 0. 5~5.5mol%, the content of Nd 2 O 3 is a 0.5~4mol%, that the total amount of Y 2 O 3, La 2 O 3 and Nd 2 O 3 is 6～8Mol% Is preferred. If it deviates from this range, various properties such as durability, sensitivity, responsiveness, alkali resistance, low alkali error, etc. of the response glass 5 may be deteriorated and may not be put to practical use. When the response glass 5 is a thick tube (tough response glass), the La 2 O 3 content is suppressed to 4 mol% or less in order to prevent devitrification at the time of fusion bonding with the support glass tube 4. It is preferable.
以下に実施例を掲げて本発明を更に詳しく説明するが、本発明はこれら実施例に限定されないのは言うまでもない。 Hereinafter, the present invention will be described in more detail with reference to examples, but it goes without saying that the present invention is not limited to these examples.
＜応答ガラスの作製＞
下記の表１に記載の組成で、Ｌａ2Ｏ３、Ｍｅ2Ｏ３、及び、Ｙ２Ｏ３又はＳｃ２Ｏ３を含有する各種リチウムシリケートガラスからなる応答ガラスを作製した。なお、いずれのガラスにも微量成分としてＣｓ２Ｏ、ＢａＯ及びＴａ２Ｏ５を添加した。
<Production of response glass>
Responsive glasses made of various lithium silicate glasses containing La 2 O 3 , Me 2 O 3 , and Y 2 O 3 or Sc 2 O 3 with the composition shown in Table 1 below were prepared. Incidentally, Cs 2 O as a minor component in any of the glass, was added BaO and Ta 2 O 5.
＜耐アルカリ性試験＞
得られた応答ガラスのうち、実施例１、３及び４（それぞれ３サンプルずつ）並びに比較例１を備えたｐＨ応答性ガラス電極と、Ｍｅ2Ｏ３（ＭｅはＬａ以外のランタノイド）、Ｙ２Ｏ３及びＳｃ２Ｏ３を含まない応答ガラスを備えたｐＨ応答性ガラス電極（従来他社製品）とを、０．１Ｍの水酸化ナトリウム水溶液に５週間浸漬し、その前後の、感度（％）、アルカリ誤差（ｍＶ）、及び、水道水９０％応答（ｓ）について調べた。結果は下記表２に示した。
<Alkali resistance test>
Among the obtained response glasses, pH-responsive glass electrodes provided with Examples 1, 3 and 4 (each 3 samples) and Comparative Example 1, Me 2 O 3 (Me is a lanthanoid other than La), Y 2 A pH-responsive glass electrode (conventional product) comprising a response glass that does not contain O 3 and Sc 2 O 3 is immersed in a 0.1 M aqueous sodium hydroxide solution for 5 weeks, and the sensitivity (%) before and after that is immersed. , Alkali error (mV), and tap water 90% response (s). The results are shown in Table 2 below.
得られた結果より、感度に関しては、ＬａとＬａ以外のランタノイドとを併用しても高い感度が維持され、また、０．１Ｍの水酸化ナトリウム水溶液に５週間浸漬した後も、感度はほとんど低下しないことが明らかとなった。なお、ここで、感度とは、ネルンスト応答における理論値を１００％として表した値である。 From the results obtained, high sensitivity is maintained even when La and a lanthanoid other than La are used in combination, and the sensitivity is almost reduced even after being immersed in a 0.1 M aqueous sodium hydroxide solution for 5 weeks. It became clear not to. Here, the sensitivity is a value expressed with the theoretical value in the Nernst response as 100%.
また、アルカリ誤差に関しては、ＬａとＬａ以外のランタノイドとを併用しても充分実用に耐えうる性能が維持されることが明らかとなった。なかでも、Ｌａ以外のランタノイドとしてＮｄが用いられた実施例１はアルカリ誤差が小さく優れていた。 In addition, with regard to the alkali error, it has become clear that even if La and a lanthanoid other than La are used in combination, the performance sufficient for practical use is maintained. Among them, Example 1 in which Nd was used as a lanthanoid other than La was excellent with a small alkali error.
更に、水道水９０％応答に関しては、ＬａとＬａ以外のランタノイドとを併用した場合は極めて応答速度が速くなり、０．１Ｍの水酸化ナトリウム水溶液に５週間浸漬した後も、優れた応答性が維持されることが明らかとなった。 Furthermore, regarding the 90% response of tap water, when La and a lanthanoid other than La are used in combination, the response speed is extremely fast, and excellent response is achieved even after being immersed in a 0.1 M sodium hydroxide aqueous solution for 5 weeks. It became clear that it was maintained.
＜中和価試験＞
得られた応答ガラスのうち実施例１のものを備えたｐＨ応答性ガラス電極（比較電極との複合型）を用いて、エンジンオイルの中和価滴定（酸価）を４回行なった。なお、比較として、Ｍｅ2Ｏ３（ＭｅはＬａ以外のランタノイド）、Ｙ２Ｏ３及びＳｃ２Ｏ３を含まない応答ガラスを備えた従来他社製品のｐＨ応答性ガラス電極（比較電極との複合型）用いて、同様にエンジンオイルの中和価滴定を行なった。
<Neutralization value test>
Among the obtained response glasses, neutralization titration (acid value) of engine oil was performed 4 times using a pH responsive glass electrode (composite type with a comparative electrode) provided with the glass of Example 1. As a comparison, a pH-responsive glass electrode of a conventional product having a response glass not containing Me 2 O 3 (Me is a lanthanoid other than La), Y 2 O 3 and Sc 2 O 3 (composite with a comparison electrode) Type), and neutralization titration of engine oil was performed in the same manner.
中和価滴定は、ガラス電極として比較電極との複合型を用いたこと、及び、０．１ｍｏｌ／Ｌ水酸化カリウム溶液を１分間に０．１ｍｏｌずつ滴定したこと以外は、ＪＩＳ Ｋ ２５０１に規定の中和価試験方法のうち電位差滴定法（酸価）に準拠して行い、試料のはかり採り量は５．０±０．５ｇとした。結果は、図２（滴定曲線）及び図３（変曲点検出）に示した。 Neutralization titration is specified in JIS K 2501 except that a composite electrode with a reference electrode was used as a glass electrode and that 0.1 mol / L potassium hydroxide solution was titrated 0.1 mol per minute. The neutralization value test method was conducted according to the potentiometric titration method (acid value), and the sample was weighed 5.0 ± 0.5 g. The results are shown in FIG. 2 (titration curve) and FIG. 3 (inflection point detection).
得られた結果より、従来他社製品に比べて実施例１の方が、応答速度が速いことより、滴定曲線のＳ字カーブが明瞭に確認され、その変曲点である中和点が検出しやすいことが明らかとなった。 From the obtained results, the S-curve of the titration curve is clearly confirmed and the neutralization point that is the inflection point is detected because the response speed of Example 1 is faster than that of the conventional products of other companies. It became clear that it was easy.
１ ・・・ガラス電極
５ ・・・応答ガラス
DESCRIPTION OF SYMBOLS 1 ... Glass electrode 5 ... Response glass
Claims (9)
前記Ｍｅ2Ｏ３が、Ｙｂ 2 Ｏ ３ であることを特徴とする応答ガラス。 A responsive glass used for a pH-responsive glass electrode, which contains at least La 2 O 3 and Me 2 O 3 (Me is a lanthanoid other than La) as its component composition, and additionally La 2 O 3 and Me 2 O 3 containing a smaller amount of Y 2 O 3 or Sc 2 O 3 than the total amount of 3 ,
The response glass, wherein the Me 2 O 3 is Yb 2 O 3 .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2008141899A JP5335288B2 (en) | 2008-05-30 | 2008-05-30 | Glass electrode and its response glass |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2008141899A JP5335288B2 (en) | 2008-05-30 | 2008-05-30 | Glass electrode and its response glass |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2009288117A JP2009288117A (en) | 2009-12-10 |
| JP5335288B2 true JP5335288B2 (en) | 2013-11-06 |
Family
ID=41457467
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2008141899A Active JP5335288B2 (en) | 2008-05-30 | 2008-05-30 | Glass electrode and its response glass |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5335288B2 (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5349394B2 (en) * | 2010-03-31 | 2013-11-20 | 株式会社堀場製作所 | Glass electrode |
| JP6603135B2 (en) * | 2014-01-31 | 2019-11-06 | 株式会社パイロットコーポレーション | Internal liquid for reference electrode, reference electrode and glass electrode |
| CH713989B1 (en) * | 2017-07-14 | 2022-05-13 | Horiba Advanced Techno Co Ltd | Reactive glass and glass electrode. |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP3591390A1 (en) * | 2006-09-06 | 2020-01-08 | HORIBA, Ltd. | Glass electrode and sensitive glass for the glass electrode |
-
2008
- 2008-05-30 JP JP2008141899A patent/JP5335288B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| JP2009288117A (en) | 2009-12-10 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP5073089B2 (en) | Glass electrode and its response glass | |
| US7790323B2 (en) | Polymer electrolyte, half-cell for electrochemical measurements, as well as the use thereof | |
| JP5335288B2 (en) | Glass electrode and its response glass | |
| Shibata et al. | Potentiometric determination of pH values of dilute sulfuric acid solutions with glass combination electrode equipped with ionic liquid salt bridge | |
| Shibata et al. | Stability of a Ag/AgCl reference electrode equipped with an ionic liquid salt bridge composed of 1-methyl-3-octylimidazolium bis (trifluoromethanesulfonyl)-amide in potentiometry of pH standard buffers | |
| CN103063726A (en) | Detection method for chlorine ion content in lithium-ion battery electrolyte | |
| Han et al. | All solid state hydrogen ion selective electrode based on a tribenzylamine neutral carrier in a poly (vinyl chloride) membrane with a poly (aniline) solid contact | |
| US20120318684A1 (en) | pH Electrode and Electrolyte | |
| JPWO2009078418A1 (en) | Ion selective electrode | |
| US20100230279A1 (en) | Fluoride ion selective electrode | |
| US3219556A (en) | Ion measurement apparatus and method | |
| JP2005049190A (en) | Glass electrode | |
| US3372104A (en) | Glass electrode composition | |
| Masadome et al. | Potentiometric titration of polyhexamethylene biguanide hydrochloride with potassium poly (vinyl sulfate) solution using a cationic surfactant-selective electrode | |
| US10145814B2 (en) | Internal solution for reference electrode, reference electrode, and glass electrode | |
| Mikhelson | Development of Ion-selective Electrodes in Russia in 1991–2010 | |
| Michalska et al. | Effect of interferents present in the internal solution or in the conducting polymer transducer on the responses of ion-selective electrodes | |
| JP4824489B2 (en) | Reference electrode, ion concentration measuring device using the reference electrode, reference electrode internal solution, method for adjusting pH of reference electrode internal solution, and salt bridge | |
| Covington | Procedures for testing pH responsive glass electrodes at 25, 37, 65 and 85 C and determination of alkaline errors up to 1 mol dm-3 Na+, K+, Li+ | |
| JP5349394B2 (en) | Glass electrode | |
| Ganjali et al. | A novel Ho (III) sensor based on N, N'-bis (2-pyridinecarboxamide)-1, 2-benzene as a neutral ion carrier | |
| CA2426476C (en) | Fluoride-sensitive electrode | |
| JP7116611B2 (en) | Responsive glass and glass electrode | |
| JPH03505483A (en) | solid phase ion selective electrode | |
| Yokono et al. | Local anesthetic-sensitive electrodes: preparation of coated-wire electrodes and their basic properties in vitro |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20101215 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20120207 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20120405 |
|
| A02 | Decision of refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A02 Effective date: 20120501 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20120731 |
|
| A911 | Transfer to examiner for re-examination before appeal (zenchi) |
Free format text: JAPANESE INTERMEDIATE CODE: A911 Effective date: 20120807 |
|
| A912 | Re-examination (zenchi) completed and case transferred to appeal board |
Free format text: JAPANESE INTERMEDIATE CODE: A912 Effective date: 20121109 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20130731 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 5335288 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |