JP5804421B2 - Treatment method for suppressing alkali metal elution from glass lining surface, alkali metal elution suppression glass lining, and glass lining structure - Google Patents

Description

  The present invention relates to a glass lining having a metal substrate layer, an undercoating glass lining layer (undercoating GL layer), and an uppermost glass lining layer (overcoating GL layer) from the surface of the overcoating GL layer. The present invention relates to a treatment method for suppressing elution of alkali metal. Moreover, this invention relates to the structure made from GL comprised from the alkali metal elution suppression glass lining (GL) obtained by such a processing method, and the said alkali metal elution suppression GL.

A glass layer mainly composed of siliceous (SiO ₂ ) is firmly fired and bonded to the metal surface. Among them, glass lining (GL) is particularly excellent in acid resistance, alkali resistance and heat resistance. Call. GL used for GL devices and the like is manufactured by baking an undercoat glaze on a metal substrate such as a low-carbon steel plate or a stainless steel plate, and then baking an overcoat glaze with high corrosion resistance.

The glass layer for GL is made of calcium oxide (CaO), sodium oxide (Na ₂ O) or potassium oxide (K ₂ O) in order to obtain high chemical resistance, adhesion to a metal substrate, workability, etc. Such various components are contained. Moreover, since the undercoat glaze and the overcoat glaze use natural minerals as raw materials, they contain a small amount of components derived from natural minerals that are not intentionally added.

Among the components contained in GL, those that are particularly easy to elute are alkali components (alkali metal ions) such as Na ⁺ (sodium ions), K ⁺ (potassium ions) or Li ⁺ (lithium ions). Although a trace amount of alkali metal components are eluted as ions from the GL surface layer, even if a trace amount is mixed into the contents of the GL structure, there is no problem if it is normal. However, if the product in the GL structure is a field where ultra-high purity is required, such as in the semiconductor industry, a trace amount of alkali components eluted from the GL layer may cause serious contamination. .

  Therefore, depending on the user of the GL structure, the GL structure is acid-washed and dealkalized before use to reduce the elution of alkali components (including alkaline earth components, the same shall apply hereinafter). Nation is reduced.

  Patent Document 1 discloses a glass protective film by applying inorganic polysilazane on an alkali-containing glass as a means for suppressing alkali metal elution from an alkali-containing glass such as soda glass and baking it at a temperature of 200 ° C. or higher. Is disclosed.

In Patent Document 2, the surface of the GL layer is coated with a paste of SiO ₂ , ZrO ₂ , Cr ₂ O ₃ with an aqueous ammonium sulfate solution, and heat-treated at 300 ° C. to 600 ° C. The thermal diffusion removal is disclosed. Patent Document 2 also discloses that after the GL layer is dealkalized, it is subjected to silica coating by a sol-gel method to prevent elution of metal ions from the GL layer.

In Patent Document 3, in order to suppress elution of an alkaline component from the GL surface, with respect to GL composed of a metal substrate and two GL layers, SiO ₂ or ZrO ₂ is formed on the surface of the overcoat GL layer (outer surface). A technique is disclosed in which a PTFE layer is further formed after a dealkalization treatment is performed by applying a paste containing and heat-treating.

JP-A-4-132635 JP 2001-131777 A JP 2009-197252 A

  In order to suppress alkali metal elution, GL structures are generally washed with acid before use. However, when the effect of alkali component elution reduction is low and the effect has ceased, acid washing is performed again on site. A large cleaning device and a large amount of acid solution are required because of the need to do so. Further, since it is necessary to treat the waste acid after washing, the treatment space, washing cost and treatment cost are inevitably increased.

  Further, the example of Patent Document 1 only discloses a method of firing a polysilazane coat (polysilazane protective layer) at a high temperature of 500 ° C., and such high temperature firing is performed at a temperature close to the glass transition point of GL. Therefore, there is a possibility that tensile stress is generated in the glass and the glass is easily broken.

  Similarly, since the silica coating disclosed in Patent Document 2 must be heat-treated at a high temperature of 500 ° C., tensile stress is generated in the glass and the glass may be easily broken.

  In the treatment method of Patent Document 3, since PTFE is used, there is a problem that it cannot be used in a high temperature environment.

  An object of the present invention is to provide a GL treatment method for effectively suppressing alkali metal elution from the overcoat GL layer, and an alkali metal elution suppression GL obtained by such a treatment method.

The inventor has intensively studied a method for suppressing alkali metal elution from the overcoat GL layer as the outermost layer. As a result, by bringing the outermost GL layer into contact with the molten ammonium salt and applying a DC voltage between the molten liquid and GL, ammonium ions (NH ₄ ⁺ ), hydrogen ions (H ⁺ ), or oxonium Ions (H ₃ O ⁺ ) move to the overcoat GL layer, and alkali ions such as sodium ions (Na ⁺ ) or lithium ions (Li ⁺ ) near the surface of the overcoat GL layer move toward the metal substrate. As a result, the present invention has been completed.

Specifically, the present invention
About a glass lining having a metal substrate layer, an undercoating glass lining layer, and an uppermost glass lining layer,
(A) sulfuric acid, or (B) a melt containing at least one ammonium salt,
In a state where any of the above and the overlying glass lining layer are brought into contact with each other, and the sulfuric acid or the molten liquid and the metal base material layer are not brought into contact
Sulfuric acid heated to 200 ° C or higher or the molten liquid is applied to the positive electrode side, the direct current voltage is applied to the metal substrate layer as the negative electrode side, and the alkali metal near the surface of the overlying glass lining layer is moved toward the metal substrate layer Alternatively, the present invention relates to a treatment method that suppresses alkali metal elution from the surface of a top-coated glass lining layer by introducing monovalent cations in a molten solution into the glass.

Sulfuric acid heated to 200 ° C or higher, or ammonium salt heated to 200 ° C or higher and molten GL layer are brought into contact with each other, and direct current voltage is applied with sulfuric acid or molten liquid on the positive electrode side and metal substrate layer on the negative electrode side. In addition, due to the direct current voltage, alkali ions such as Na ⁺ , K ⁺ or Li ⁺ near the surface of the overcoat GL layer are moved in the direction of the metal substrate, that is, away from the surface of the overcoat GL layer. Moved. On the other hand, monovalent cations such as H ⁺ are introduced to the surface of the overlying GL layer in order to supplement the charge balance after Na ^{+ and the} like move. As a result, the alkali metal content in the vicinity of the GL layer surface is reduced, and alkali metal elution from the GL layer surface is suppressed.

  The molten salt may be able to maintain a stable molten state at the temperature at which a DC voltage is applied. For example, in the case where the molten salt is heated to 200 ° C., melted, brought into contact with the overcoat GL layer, and a DC voltage is applied, the molten salt may be in a stable molten state at 200 ° C. Similarly, when heated to 300 ° C. and melted, brought into contact with the overcoat GL layer, and a DC voltage is applied, a stable molten state at 300 ° C. is sufficient.

  The sulfuric acid is preferably anhydrous sulfuric acid.

The ammonium salt is a mixture of ammonium sulfate and ammonium hydrogen sulfate,
The mass ratio of ammonium sulfate to ammonium hydrogen sulfate in the mixture is preferably 1 or more and 4 or less. This is because the ammonium salt is in a stable molten state at 200 ° C. or higher.

  The top glass lining layer is preferably a top glass lining layer not containing K.

This is because when K ⁺ having a large ion radius moves in the overcoat GL layer, the stress generated in the overcoat GL layer is large, and thus the overcoat GL layer may be easily peeled off. The overlying GL layer not containing K is obtained by forming the GL layer using a glass frit containing no K.

The present invention also provides:
A GL having a metal substrate layer, an undercoat GL layer, and an uppermost GL layer on the outermost layer,
Sodium from upper coating GL layer surface in the following portion with a thickness 1 [mu] m, the content of potassium and lithium state, and are less than 1/10 of the upper coating sodium in the glass frit constituting the GL layer, potassium and lithium content,
The overcoat GL layer contains ammonium ions, and relates to an alkali metal elution suppression GL.

  In the GL treated by the treatment method of the present invention, hydrogen ions or ammonium ions are introduced in the vicinity of the surface of the overcoat GL layer, and alkali ions move to the metal substrate side. In order to effectively prevent alkali metal elution from the surface of the overcoat GL layer, the content of Na, K and Li in the thickness portion of 1 μm or less from the surface of the overcoat GL layer is the glass constituting the overcoat GL layer. As a measure of the content of alkali metal in the frit, it is important that it is 1/10 or less of the content of Na, K and Li.

  The “content of Na, K and Li” herein means the mol concentration of each element, and is a measure of the amount of alkali metal contained in GL.

  The alkali metal elution suppression GL of the present invention is preferably a top GL layer in which the top GL layer does not contain K.

The present invention also provides:
A GL having a metal substrate layer, an undercoat GL layer, and an uppermost GL layer on the outermost layer,
The content of sodium, potassium and lithium in the thickness portion of 1 μm or less from the surface of the overcoat GL layer is 1/10 or less of the content of sodium, potassium and lithium in the glass frit constituting the overcoat GL layer,
The present invention relates to an alkali metal elution suppression GL, wherein the overlying glass lining layer contains at least one of protons and oxonium ions.

  The present invention relates to a GL structure including the alkali metal elution suppression GL having the above configuration.

  According to the present invention, by reducing the alkali ion content in the vicinity of the surface of the overcoat GL layer for the GL having the overcoat GL layer, the alkali metal elution is effectively suppressed as compared with the conventional alkali treatment method. obtain. The method of the present invention has the advantage of being applicable to existing GL products.

The conceptual diagram explaining the implementation state of the processing method of this invention is shown. The conceptual diagram explaining the movement of the ion near the surface of the overcoat GL layer in the processing method of this invention is shown. The graph of the result of having measured distribution of each element from the surface layer to the depth direction about GL of the test example 2 is shown. The graph of the result of having measured distribution of each element from the surface layer to the depth direction about GL of Experiment 1 processed using anhydrous sulfuric acid is shown. The graph of the result of having measured distribution of each element from the surface layer to the depth direction about GL of Example 2 is shown. The graph of the result of having measured distribution of each element from the surface layer to the depth direction about GL of Example 3 is shown.

  Embodiments of the present invention will be described below. The present invention is not limited to the following description.

  FIG. 1 is a conceptual diagram illustrating an implementation state of the processing method of the present invention. Here, an embodiment using an ammonium salt will be described, but it is also possible to use sulfuric acid instead of the ammonium salt and operate in the same manner.

  In the GL 1, the undercoat GL layer 3 and the overcoat GL layer 4 are sequentially fired on the metal base 2. The example of the metal base material 2 is steel or stainless steel. The undercoat GL layer 3 can be formed by a known method, for example, a firing method, using a known glass frit for the undercoat GL layer. Similarly, the overcoat GL layer can be formed by a known method using a known glass frit for the overcoat GL layer. The thickness of the metal substrate 2, the undercoat GL layer 3, and the overcoat GL layer 4 is not particularly limited as long as a DC voltage can be applied when the metal base 2, the undercoat GL layer 4 is brought into contact with a molten salt (or sulfuric acid) heated to 200 ° C. or higher. .

  The GL 1 is attached to an insulating heat-resistant cylinder 7 (heat-resistant container) such as alumina via a gasket 6. At this time, the upper GL layer 4 is attached so as to be on the heat-resistant container 7 side. The bottom of the heat-resistant container 7 is open, and the upper surface of the overcoat GL layer 4 is exposed at the bottom of the heat-resistant container 7.

  At least one ammonium salt 5 is supplied into the heat-resistant container 7. As the ammonium salt 5, a mixture of ammonium sulfate and ammonium hydrogen sulfate is preferable. At this time, it is more preferable to use a mixture in which both are mixed such that the mass ratio of ammonium sulfate to ammonium hydrogen sulfate is 1 or more and 4 or less. The ammonium salt 5 may be composed of only an ammonium salt, and may contain components other than the ammonium salt.

  A negative electrode 8 and a positive electrode 9 are attached so that the metal substrate 2 is on the negative electrode side and the inside of the heat-resistant container 7 is on the positive electrode side, and is connected to the DC power source 10. Then, GL1 and the heat-resistant container 7 are put into a high-temperature tank and heated to the melting temperature of the ammonium salt or higher. The melting temperature is 200 ° C. or higher. By doing so, the ammonium salt 5 melts to become a melt 11 at 200 ° C. or higher, and the melt 11 and the overcoat GL layer 4 come into contact with each other. At this time, the melt 11 and the metal substrate 2 are not in contact, and the anode 9 is in contact with the melt 11.

  Even when the GL itself is set to 200 ° C. or higher, the volume resistivity of the glass is reduced and the current easily flows. From the viewpoint of facilitating current flow, the melting temperature is preferably 200 ° C. or higher, more preferably 250 ° C. or higher. The ammonium salt and GL are each preferably heated by a heating device such as an electric heater.

Thereafter, a DC voltage is applied between the negative electrode 8 and the positive electrode 9. The DC voltage is preferably 100V or more and 1000V or less. As described above, the ammonium salt 5 is a mixture of ammonium sulfate and ammonium hydrogen sulfate, and the mass ratio of ammonium sulfate to ammonium hydrogen sulfate in the mixture is preferably 1 or more and 4 or less. In this case, the DC voltage is 100V. It is preferable to set it to 1000 V or less, and more preferable to set it to 100 V or more and 600 V or less.
This is because the processing time becomes longer when the DC voltage is 100 V or less, and when it is 1000 V or more, the current that leaks on the outer surface of the heat-resistant container increases, and the efficiency decreases.

  Although depending on the thickness of the overcoat GL layer 4, the amount of alkali metal in the glass to be processed, the processing temperature, the processing voltage, or the processing thickness, the processing method of the present invention is preferably performed for 1 to 5 hours or more. For example, when a glass having a total alkali metal content of 10 to 20 mol% is treated at 200 ° C. or higher by the treatment method of the present invention, the treatment time is preferably 2 to 3 hours. In order to effectively suppress alkali metal elution, the content of Na, K, and Li in the thickness portion of 1 μm or less from the surface of the overcoat GL layer is the content of Na and Li in the glass frit constituting the overcoat GL layer. This is because it is preferably 1/10 or less of the amount.

FIG. 2 is a conceptual diagram illustrating the movement of ions in the vicinity of the overcoat GL layer in the method of the present invention (when using a molten salt). The melt 11 contains NH ₄ ⁺ , H ⁺ and oxonium ions H ₃ O ⁺ . On the other hand, the overcoat GL layer 4 mainly contains Na ⁺ , K ⁺ and Li ⁺ as alkali ions.

When a DC voltage is applied between the negative electrode 8 and the positive electrode 9, Na ⁺ , K ⁺ and Li ⁺ in the overcoat GL layer 4 move in the direction of the metal substrate on the negative electrode side. Then, instead of Na ⁺ , K ⁺ and Li ⁺ , NH ₄ ⁺ , H ⁺ and H ₃ O ⁺ in the melt 11 move into the glass layer near the surface of the overcoat GL layer 4. As a result, Na ⁺ , K ⁺ and Li ⁺ in the vicinity of the surface of the overcoat GL layer 4 are reduced, and alkali metal elution from the overcoat GL layer 4 can be effectively suppressed.

In particular, when using a molten salt containing ammonium ions, for NH ₄ ⁺ ion radius is an ion radius comparable alkali metal ions such as Na ^+, is NH ₄ ⁺ in the places where such as Na ⁺ moves By entering, the change in stress in the GL layer due to the movement of alkali metal ions such as Na ⁺ can be reduced, and it is possible to prevent breakage and peeling of the glass due to the change in stress, and it is stable with excellent corrosion resistance. A GL layer can be formed.

  In addition, by reducing the Na compound, K compound or Li compound of the glass frit of the overcoat GL layer, instead of adding an ammonium salt and constructing the overcoat GL layer, the alkali content of the overcoat GL layer is reduced. It is also conceivable to suppress alkali metal elution. However, in this case, the overlying GL layer cannot be formed because the ammonium salt is decomposed by firing during construction.

When K ⁺ moves upper coating GL layer 4, since the ion radius is extremely large compared with the Na ⁺ and Li ^+, stress generated inside the upper coating GL layer 4 is increased, the upper coating GL layer 4 There is a risk of peeling. For this reason, it is preferable to apply the processing method of the present invention to the GL in which the overcoat GL layer 4 does not contain K ⁺ . Here, “GL containing no K” means GL in which a glass frit does not actively contain a component such as potassium salt or potassium oxide, and K is inevitably contained in the glass frit. Does not mean containing GL.

When sulfuric anhydride is used, Na ⁺ , K ⁺ and Li ⁺ in the overcoat GL layer 4 move toward the metal substrate on the negative electrode side, and H ⁺ in the anhydrous sulfuric acid is overcoated GL. Move to the vicinity of the surface of the layer 4.

[Test Example 1]
On a carbon steel plate (SS400, thickness 6 mm, 110 mm × 110 mm test piece), a glass frit having the composition shown in Table 1 was applied by spraying to a thickness of 0.2 mm and fired at 920 ° C. In addition, the unit of the number in Table 1 is the mass%.

  Next, a glass frit having the composition shown in Table 2 undercoat GL (1) was applied onto the undercoat GL layer by spraying to a thickness of 1 mm, and firing was repeated a plurality of times at 850 ° C. The GL having the two GL layers thus obtained was designated as GL of Test Example 1. In addition, the unit of the number in Table 2 is mass%.

[Test Example 2]
The GL obtained in the same manner as in Test Example 1 was used as the GL of Test Example 2, except that the glass frit having the composition shown in Table 2 GL (2) was used.

(Example 1)
About GL of the test example 1, GL and sulfuric anhydride were contacted in the state heated at 200 degreeC using the apparatus as shown in FIG. A DC voltage was applied to confirm that a total of 3 coulomb charges flowed, and Na ⁺ , K ⁺ and Li ⁺ in the vicinity of the surface of the overcoat GL layer were replaced (ion exchange) with H ⁺ .

  GL and sulfuric anhydride were each heated by an electric heater (not shown). Moreover, the charge amount was measured by installing a coulomb meter in the circuit.

(Example 2)
With respect to GL of Test Example 1, a DC voltage was applied at 250 ° C. using a mixed ammonium salt obtained by mixing equimolar amounts of ammonium sulfate and ammonium hydrogen sulfate as an ammonium salt using an apparatus as shown in FIG. As in Example 1, it was confirmed that a total of 5 coulomb charges flowed using a coulomb meter, and Na ⁺ , K ⁺ and Li ⁺ in the vicinity of the surface of the overcoat GL layer were replaced with NH ₄ ⁺ (ion exchange). did.

(Example 3)
For GL of Test Example 2, a DC voltage was applied in the same manner as in Example 2, and Na ⁺ and Li ⁺ in the vicinity of the surface of the overcoat GL layer were substituted (ion exchange) with NH ₄ ⁺ .

  For the GL after the surface treatment, a low elution life, an ion exchange amount, an ion thickness, and a low elution life were measured. Table 3 shows the measurement results.

  Here, the ion exchange amount is a current flowing between the anode and the cathode during processing, and was measured by incorporating a coulomb meter in a circuit to which an electric field was applied. The ion exchange thickness is the thickness of the layer formed by the treatment, to which the alkali metal component has moved, and was measured by a glow discharge optical emission spectrometer (GDOES). The low elution life is the time until the elution value returns to the amount equivalent to the alkali metal elution amount before the treatment. The sample treated in 110 ° C. purified water is exposed for 250 hours, and the alkali metal eluted from the GL layer in the purified water. It confirmed by measuring the elution amount.

  In Example 1 using anhydrous sulfuric acid, the values of ion exchange amount, ion exchange thickness and low elution lifetime were about half as compared with Examples 2 and 3 using ammonium molten salt. It can be said that GL (non-treatment) is sufficiently suppressed in practical use from the elution of alkali metal.

  Next, the GL (untreated) of Test Example 1 and the GLs of Examples 1 to 3 are placed in a PTFE cylinder (tubular body) containing purified water through an o-ring so that the GL surface is on the inside. Attached. Each GL surface was brought into contact with purified water, and kept in an autoclave at 110 ° C. for 250 hours. Thereafter, the amounts of Na, Li and Ca eluted in the purified water are the concentrations of each ion measured by an inductively coupled plasma mass spectrometer (ICP-MS). Table 4 shows the measurement results.

  The elution amounts of GL Na, Li, and Ca in Examples 1 to 3 were less than the detection limit in the measurement method of each element. From Table 4, it was confirmed that the ammonium salt treatment, which is the treatment method of the present invention, further reduced alkali metal elution from the overcoat GL layer as compared with the treatment method using anhydrous sulfuric acid.

<Glow discharge emission spectroscopic analysis test>
FIG. 3: shows the graph of the result of having measured distribution of each element from the surface layer to the depth direction about the GL of Test Example 2 using the glow discharge emission spectroscopic analyzer (GDOES). In FIG. 3, the vertical axis indicates the relative abundance of each element (how much the element is present when the amount of the specific element at the deepest position from the measured GL surface is 1). The numerical value expressed relatively), and the horizontal axis represents the depth (thickness) from the surface of the overdrawing GL. The same applies to FIGS. 4 to 6 described later.

  On the other hand, FIG. 4 measured the distribution of each element from the surface layer to the depth direction for GL obtained in the same manner as in Example 1 except that GL heated to 205 ° C. and sulfuric anhydride were contacted. It is a graph of a result. From FIG. 4, it was confirmed that Na and Li were hardly detected in the overlying GL layer from the GL surface to about 1.5 μm by ion exchange using sulfuric anhydride. From FIG. 4, the content of Na and Li in the thickness portion of 1 μm or less from the surface of the overcoated glass lining layer was 1/10 or less of the content of Na and Li in the glass frit constituting the overcoated GL layer.

  In addition, also about GL of Example 1, as a result of measuring distribution of each element from a surface layer to a depth direction, the same result was obtained.

  FIG. 5: shows the graph of the result of having measured distribution of each element from the surface layer to the depth direction about the GL of Example 2 using the glow discharge emission spectroscopic analyzer (GDOES). From FIG. 5, it was confirmed that the GL of Example 2 hardly detected Na and Li in the overlying GL layer from the GL surface to about 4.0 μm. From FIG. 5, the content of Na and Li in the thickness portion of 1 μm or less from the surface of the overcoated glass lining layer was 1/10 or less of the content of Na and Li in the glass frit constituting the overcoated GL layer.

  FIG. 6 shows a graph of the results of measuring the distribution of each element in the depth direction from the surface layer, using a glow discharge optical emission spectrometer (GDOES), for the GL of Example 3. From FIG. 6, it was confirmed that the GL of Example 3 hardly detected Na and Li in the overlying GL layer from the GL surface to about 6.0 μm. From FIG. 6, the content of Na and Li in the thickness portion of 1 μm or less from the surface of the overcoated glass lining layer was 1/10 or less of the content of Na and Li in the glass frit constituting the overcoated GL layer.

<Ammonium measurement test in GL layer>
About untreated GL and GL of Example 2, N (nitrogen) content (mass%) in the glass on the surface of GL was measured by X-ray photoelectron spectroscopy (XPS). As a result, in the untreated GL, the N content was 0% by mass, and in the GL of Example 2, it was 3.57% by mass.

Furthermore, the above-mentioned two types of GL were attached to a PTFE cylinder (tubular body) containing purified water through an o-ring so that the GL surface was on the inside. Each GL surface was brought into contact with purified water, and kept in an autoclave at 110 ° C. for 600 hours to elute elution components on the surface of the GL layer in purified water. Thereafter, the ammonium ion concentration in the purified water was measured by indophenol blue absorptiometry. As a result, in the untreated GL, the NH ₄ ⁺ concentration was 0 mg / L, whereas in the GL of Example 2, the NH ₄ ⁺ concentration was 0.01 mg / L, and NH ₄ ⁺ was present in the GL layer. It was confirmed that it was incorporated.

  Thus, by applying the treatment method of the present invention to GL, alkali metals near the surface of the overcoat GL layer, which cause alkali metal elution, can be reduced.

  INDUSTRIAL APPLICABILITY The present invention is useful in a technical field for producing a product in which an alkali metal (alkali metal ion) eluted from GL becomes a problem, such as in the semiconductor field or the chemical field.

1: GL
2: Metal base material 3: Undercoat GL layer 4: Overcoat GL layer 5: Ammonium salt 6: Gasket 7: Heat-resistant cylinder (heat-resistant container)
8: Negative electrode 9: Positive electrode 10: DC power supply 11: Melt

Claims (7)

About glass lining having a metal substrate layer, an undercoating glass lining layer, and an overcoating glass lining layer,
(A) sulfuric acid, or (B) a melt containing at least one ammonium salt,
In a state where any of the above and the overlying glass lining layer are brought into contact with each other, and the sulfuric acid or the molten liquid and the metal substrate layer are not brought into contact with each other,
Sulfuric acid heated to 200 ° C or higher or the molten liquid is applied to the positive electrode side, the direct current voltage is applied to the metal substrate layer as the negative electrode side, and the alkali metal near the surface of the overlying glass lining layer is moved to the metal substrate layer side Or the processing method which suppresses the elution of the alkali metal from the surface of an upper glass lining layer by introduce | transducing the monovalent cation in a melt into glass. The ammonium salt is a mixture of ammonium sulfate and ammonium hydrogen sulfate;
The processing method according to claim 1, wherein a mass ratio of ammonium sulfate to ammonium hydrogen sulfate in the mixture is 1 or more and 4 or less.   The processing method according to claim 1 or 2, wherein the upper glass lining layer is an upper glass lining layer not containing potassium. A glass lining having a metal substrate layer, an undercoating glass lining layer, and an overcoating glass lining layer,
Sodium from upper coating glass lining layer surface in the following portion with a thickness 1 [mu] m, the content of potassium and lithium state, and are less than 1/10 of the upper coating sodium in the glass frit constituting the glass lining layer, potassium and lithium content ,
An alkali metal elution suppression glass lining, wherein the overlying glass lining layer contains ammonium ions . A glass lining having a metal substrate layer, an undercoating glass lining layer, and an overcoating glass lining layer,
Sodium from upper coating glass lining layer surface in the following portion with a thickness 1 [mu] m, the content of potassium and lithium state, and are less than 1/10 of the upper coating sodium in the glass frit constituting the glass lining layer, potassium and lithium content ,
An alkali metal elution suppression glass lining, wherein the overlying glass lining layer contains at least one of a proton and an oxonium ion . The alkali metal elution suppression glass lining according to claim 4 or 5 , wherein the upper glass lining layer is an upper glass lining layer not containing potassium. The glass lining structure comprised from the alkali metal elution suppression glass lining of any one of Claims 4 thru | or 6 .