JPH11286628A - Method for preventing corrosion of oxide semiconductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a coating material which, when applied to the surface of a semiconductor, can prevent the surface from being corroded even when an electrolyte is formed thereon in e.g. a high-temperature environment by incorporating a film-forming agent with an ion exchange material. SOLUTION: This material comprises a film-forming agent desirably being one forming a hydrophilic film or one forming a hydrophobic film and an ion exchange material desirably being an ion exchange resin or an inorganic ion exchange substance. It is desirable that the film-forming agent which forms a hydrophilic film is a hydrophilic-group-containing acrylic, alkyd, melamine, urea, phenolic, epoxy, cellulose, urethane, polyacetal, polyvinyl alcohol, or vinyl chloride resin. It is desirable that the film-forming agent which forms a hydrophobic agent is a cellulose, alkyd, melamine, urea, vinyl chloride, butyral, aminoalkyd, acrylic, epoxy, unsaturated polyester, urethane, olefin, or vinyl acetate resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid crystal display or an electroluminescence display device.
For oxide semiconductors such as TO (Indium Tin Oxide),
In high-humidity environments, environments with drastic temperature changes, or environments where sea salt particles or dust containing salt can adhere, even if the electrolyte forms on the surface of the oxide semiconductor due to condensation or salt deliquescence, The present invention relates to a method for preventing corrosion and wire breakage due to corrosion.

[0002]

2. Description of the Related Art An oxide semiconductor is considered to be chemically stable because it is an oxide, but it is known that it corrodes in an atmospheric environment. For example, ITO used for an electrode of a liquid crystal display device is corroded to cause disconnection (Japanese Patent Application Laid-Open No. 58-178325), but the mechanism of this corrosion was not clear.

[0003] Therefore, the present inventors have found that when an oxide semiconductor to which a voltage is applied is in contact with an electrolytic solution, a current flowing through the oxide semiconductor also flows into the electrolytic solution, and the current flows from the electrolytic solution to the oxide semiconductor. It has been clarified that the oxide semiconductor is reduced by an electrochemical reaction and corrodes at a portion where a current flows (cathode portion) (42nd Corrosion Prevention Symposium, Corrosion Prevention Society, D-203S).

Here, ATO (Antimony
Electrolyte (0.1N-Na ₂ ) on the surface of doped Tin Oxide
The mechanism of corrosion of ATO when (SO ₄ aqueous solution) is dropped will be described with reference to FIG. FIG. 7 is a schematic diagram for explaining the corrosion mechanism of ATO. 7, reference numeral 20 denotes a power source, 21 denotes an Ag anode, 22 denotes an Ag cathode, and 23 denotes an AT.
O, 24 glass substrate, 25 is a droplet of 0.1N-Na ₂ SO ₄ aqueous solution, 26 arrow current flow, 27 is an anode section, 28 the cathode portion, 29 moves width of the droplet 30 A
This is the corroded part of TO. In FIG. 7, the droplet 25 is shown larger than the actual one for understanding the corrosion mechanism.
The size (diameter) of 5 is about 3 mm.

Next, the corrosion mechanism of ATO will be described with reference to FIG.

In the first stage of the ATO corrosion mechanism shown in FIG. 7 (a), when a direct current is applied between Ag electrodes, it is estimated that an electrocapillary phenomenon (a phenomenon in which surface tension is changed by the ATO electrode potential). Due to this phenomenon, the edge of the droplet moves toward the Ag cathode on the glass substrate, and the shape of the semi-elliptical droplet is distorted. Then, A shown in FIG.
In the second stage of the TO corrosion mechanism, ATO located at the end of the distorted droplet towards the Ag cathode is reduced and eroded. At this time, air bubbles are generated from the Ag cathode side end and the Ag anode side end of the droplet 25. Ag of droplet
At the end on the anode side, ATO becomes the anode, and it is considered that water was electrolyzed according to the formula (1): 2H ₂ O → O ₂ + 4H ⁺ + 4e ⁻ , and O ₂ was generated. On the other hand, at the end of the droplet on the Ag cathode side,
ATO serves as a cathode, and it is considered that water is electrolyzed according to the formula (2): 2H ₂ O + 2e ⁻ → H ₂ + 2OH ⁻ to generate H ₂ , and further, the formula (3): SnO ₂ + 4H ⁺ + 2e ⁻ → Sn ²⁺ + 2H ₂
ATO is reduced and corroded according to O 2.

Further, in the third stage of the ATO corrosion mechanism shown in FIG. 7C, the ATO is corroded and the droplet comes into contact with the glass substrate. The droplet penetrates the corroded portion from the ATO surface, and the corroded area further expands at the Ag anode side end of the droplet. When the substrate is made of a thermoplastic resin such as acrylic resin or polyethylene terephthalate (PET), the droplets are hard to move even if the ATO is corroded because the substrate has poorer wettability than glass. , ATO have the same corrosion mechanism.

Further, the corrosion mechanism of ITO is the same as that of ATO, and the formula (4): In ₂ O ₃ + 6H ⁺ + 4e ⁻ → 2In ³⁺ +3
H ₂ O, and formula (5): SnO ₂ + 4H ⁺ + 2e ⁻ → Sn ²⁺ + 2H ₂
The ITO is reduced and corroded according to O 2.

As described above, the mechanism of corrosion of an oxide semiconductor in an atmospheric environment can be described. Note that when no voltage is applied, the oxide semiconductor is not reduced and does not corrode even when the oxide semiconductor comes into contact with the electrolytic solution.

Further, the present inventors have studied the conditions under which a voltage applied oxide semiconductor is corroded by a general electrolytic solution, and as a result, the following was found. That is, (1) The oxide semiconductor corrodes regardless of the pH of the electrolytic solution. In the case where the electrolyte is strongly acidic or strongly alkaline, the oxide semiconductor can corrode even when no voltage is applied. For example, the corrosion of ITO in a strongly acidic aqueous solution occurs according to the formula (6): In ₂ O ₃ + 6H ⁺ → 2In ³ + + 3H ₂ O and the formula (7): SnO ₂ + 4H ⁺ → Sn ⁴⁺ + 2H ₂ O .

(2) The oxide semiconductor is easily corroded when the conductivity of the electrolytic solution is high, and hardly corroded when the conductivity of the electrolytic solution is low. This is because the current flowing in the oxide semiconductor does not flow in the electrolytic solution and no electrochemical reaction occurs. For example, the conductivity is 10 μS / cm (at 25 ° C.)
Even if the water exists on the surface of the oxide semiconductor, the oxide semiconductor does not corrode.

In general, when an oxide semiconductor is exposed to the air, sea salt particles, salt-containing dust, and the like may adhere. When these salts form an electrolytic solution by deliquescence or dew condensation, the oxide semiconductor is reduced and corroded when a voltage is applied.

Therefore, for example, Japanese Patent Application Laid-Open No. 58-17832 discloses
In Japanese Patent Application Laid-Open No. 5 (1999) -2005, there is disclosed a technique of covering the surface of an oxide semiconductor with an insulating film in order to prevent corrosion of the oxide semiconductor. FIG. 8 shows a partial schematic cross-sectional view of a liquid crystal display device based on the conventional technology. 8, 31 is an upper plate, 32
Is a lower plate, 33 is a sealing portion, 34 is an alignment film, 35 is an insulating film, 36 is a liquid crystal, 37 is an upper plate polarizing plate, 38 is a lower plate polarizing plate, 39 is a transparent conductive film, 40 is conductive rubber, 41 Is a liquid crystal display element driving circuit board, and 42 is a conductive pattern. According to this technique, the surface of a transparent conductive film (oxide semiconductor) such as ITO exposed to the air environment is prevented from being corroded by coating with an insulating film such as SiO ₂ . However, if there is a gap in the insulating film that can reach the oxide semiconductor such as a pinhole,
There is a problem that the electrolytic solution corrodes the oxide semiconductor through the gap.

[0014]

SUMMARY OF THE INVENTION As described above, the object of the present invention is to provide a dehumidifying or salt deliquescence in a high humidity environment, an environment in which temperature changes drastically, or an environment where sea salt particles or dust containing salt can adhere. An object of the present invention is to provide a method for preventing corrosion of an oxide semiconductor so that the oxide semiconductor is not deteriorated by corrosion when an electrolytic solution is formed on the surface of the oxide semiconductor.

[0015]

SUMMARY OF THE INVENTION The present invention relates to a paint for preventing corrosion of an oxide semiconductor, comprising a film-forming agent and an ion-exchange material.

In this case, the film forming agent is preferably a hydrophilic film forming agent.

Further, the hydrophilic film forming agent is an acrylic resin, an alkyd resin, a melamine resin, a urea resin, a phenol resin, an epoxy resin, a cellulose resin, a urethane resin, a polyacetal resin, a polyvinyl alcohol resin or a vinyl chloride resin having a hydrophilic group. It is preferably a resin.

It is preferable to use water and / or a hydrophilic organic solvent as a solvent.

Preferably, the film forming agent is a hydrophobic film forming agent.

The hydrophobic film-forming agent may be a cellulose resin, an alkyd resin, a melamine resin, a urea resin, a vinyl chloride resin, a butyral resin, an aminoalkyd resin, an acrylic resin, an epoxy resin, an unsaturated polyester resin, a urethane resin, an olefin resin. Alternatively, it is preferably a vinyl acetate resin.

It is preferable to use a hydrophobic organic solvent as a solvent.

It is preferable that a solvent is contained or not.

It is preferable that the film-forming agent contains no solvent, and is an epoxy resin, a urethane resin, an unsaturated polyester resin or a silicone resin.

Further, the film forming agent is preferably chloroprene rubber, nitrile rubber, styrene-butadiene rubber, silicone rubber, poly-n-butyl acrylate, glue or starch paste.

Further, it is preferable that the ion exchange material is an ion exchange resin.

The ion exchange resin is preferably at least one selected from the group consisting of a cation exchange resin and an anion exchange resin.

The cation exchange resin is preferably a strongly acidic cation exchange resin.

Preferably, the anion exchange resin is a strongly basic anion exchange resin.

It is preferable that the ion exchange material is an inorganic ion exchange substance.

Further, it is preferable that the inorganic ion exchange material is one selected from the group consisting of antimony hydroxide, zirconium phosphate, hydrosaltite and hydroxyapatite.

Preferably, the ion-exchangeable material is 0.2 to 99.8% by weight of the solid content of the paint.

It is preferable that the ion exchange material is granular and has an average particle size of 1 to 1000 μm.

The present invention relates to a method for preventing corrosion of an oxide semiconductor, which comprises applying a paint containing a film-forming agent and an ion-exchange material to the surface of the oxide semiconductor.

[0034] The present invention also relates to a liquid crystal display device including the oxide semiconductor obtained by applying the paint.

Further, a surface of the oxide semiconductor which is exposed to the air environment, or a surface of a metal film formed on the surface of the oxide semiconductor which is exposed to the air environment,
It is preferable to apply the paint.

Further, it is preferable that the liquid crystal is sealed between the substrates by using a sealing member, and that the coating material is applied to the surface of the substrate or the substrate and the sealing member.

Further, the present invention also relates to an antifogging and defrosting heater using an oxide semiconductor obtained by applying the coating material.

In addition, a surface of the oxide semiconductor which is exposed to the air environment, or a surface of a metal film formed on the surface of the oxide semiconductor which is exposed to the air environment,
It is preferable to apply the paint.

[0039]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a coating for preventing corrosion of an oxide semiconductor, comprising a film-forming agent and an ion-exchange material.

As described above, the reason that the oxide semiconductor is corroded is that the current flowing through the oxide semiconductor also flows through the electrolyte present on the semiconductor surface. Therefore, in the present invention, an ion-exchange material is used as a component of the paint, and the electrolyte in the electrolytic solution is trapped by the ion-exchange material to lower the conductivity, so that a pinhole is formed in the coating film. Even if the oxide semiconductor is not reduced, it is not corroded. That is, the present invention basically intends to capture an electrolyte (ion) contained in an electrolytic solution by the ion exchange ability of an ion exchange material and to prevent corrosion of an oxide semiconductor caused by the movement of the ion. It is.

Therefore, even if the electrolyte is strongly acidic or strongly alkaline, the electrolyte is trapped by the ion-exchange material, the conductivity of the electrolyte decreases, and the pH shifts to near neutrality. Does not corrode the oxide semiconductor.

The oxide semiconductor used in the present invention is desired to solve the problem that it can be electrochemically reduced and corroded, and is not particularly limited as long as it is a conventional one. ITO (tin-doped indium oxide), ATO (antimony-doped tin oxide), AZO (aluminum-doped zinc oxide), In ₂ O ₃ (indium oxide), SnO ₂ (tin oxide), ZnO, CdO, TiO ₂ , CdIn ₂ O ₄ , Cd ₂
SnO ₄ , Zn ₂ SnO _{4 and the} like.

The shape of the oxide semiconductor to be subjected to the corrosion prevention treatment of the present invention is not particularly limited, but is, for example, a film formed by vapor deposition, sputtering, or spraying.

Next, the paint applied to the oxide semiconductor will be described.

The paint contains a film forming agent and an ion exchange material.

First, as a film-forming agent, a film-forming agent is used to form a coating film on an oxide semiconductor to hold the ion-exchangeable material and to uniformly disperse the ion-exchangeable material in the coating material. Can be used as long as they can be used in the field of paints. Those having excellent adhesion to an oxide semiconductor are preferable.

The film-forming agent used in the present invention includes, for example, a hydrophilic film-forming agent and a hydrophobic film-forming agent.

The hydrophilic film-forming agent is preferred in that it can easily trap and remove salts because it is easy to dissolve the electrolyte, and the hydrophobic film-forming agent is preferred in that it has a high drying rate and is excellent in workability.

Examples of the hydrophilic film forming agent include a hydrophilicized acrylic resin having a hydrophilic group such as a carboxyl group, a hydroxyl group and an amino group, an alkyd resin, a melamine resin, a urea resin, a phenol resin, an epoxy resin, and a cellulose. Resin, urethane resin, polyacetal resin, polyvinyl alcohol resin, vinyl chloride resin and the like can be mentioned. Among these, acrylic resins are preferred from the viewpoint of quick drying and curing at room temperature.

Examples of the hydrophobic film forming agent include cellulose resin, alkyd resin, melamine resin, urea resin, vinyl chloride resin, butyral resin, aminoalkyd resin, acrylic resin, epoxy resin, unsaturated polyester resin, urethane resin, and olefin. Resin (for example, polyethylene, polypropylene, etc.) or vinyl acetate resin is exemplified. Among these, from the point of quick drying,
Cellulose resins are preferred.

Also, in fields other than paints, for example, adhesives,
Film forming agents used in the fields of sealing agents, pressure-sensitive adhesives and the like can also be used. Such film forming agents include, for example, chloroprene rubber, nitrile rubber, styrene butadiene rubber, silicone rubber, poly-
Examples include n-butyl acrylate, glue, starch paste and the like.

Here, the content of the film-forming agent in the coating material is set at 0.1% of the solid content of the coating material in view of the strength and adhesion of the coating film, the viscosity, and the sedimentation property of the ion exchange material.
It is preferably from 2 to 99.8% by weight, more preferably from 20 to 99.8% by weight.
Particularly preferred is 80% by weight.

Next, the ion exchange material will be described. The ion-exchange material used in the present invention is roughly classified into an ion-exchange resin which is an organic compound and an inorganic ion-exchange substance, all of which can be used alone or in combination. Use of an ion exchange resin is advantageous in that the specific gravity is small, and use of an inorganic ion exchange material is advantageous in that heat resistance is good.

When the ion exchange materials are classified from another viewpoint, they are classified into cation exchange materials and anion exchange materials. The cation exchange material is such that the electrolyte ion is a cation (for example, an alkali metal ion such as Na, K, and Li;
Other metal ions such as Ag, Cu, Fe, Pb, Sn, Zn, Mg, Ca; tetramethylammonium ion;
(Ammonium ion such as trimethylammonium ion). In the anion exchange material, the electrolyte ion is an anion (eg, a halogen ion such as Cl, Br, I; an oxide ion such as SO ₄ , NO ₃ , NO ₂ );
Used for organic acid ions such as formic acid, acetic acid and phthalic acid. Of course, both ion exchange materials may be used in combination.

The cation-exchange material and the anion-exchange material are further respectively a strongly acidic cation-exchange material, a weakly acidic cation-exchange material and a strongly basic anion-exchange material and a weakly basic anion-exchange material. Divided into materials. These modes of use are determined according to the target electrolyte.
This will be described later.

As described above, the ion exchange resin used in the present invention includes a cation exchange resin and an anion exchange resin.

Cation exchange resins are further classified into strongly acidic ones and weakly acidic ones, and any of the cation exchange resins can be used in the present invention.

The strong acidic cation exchange resin includes, for example, those having a styrene-divinylbenzene copolymer, a phenol formalin resin or the like as a base and having a sulfonic acid group as an ion exchange group. These are, for example, Amberlite-IR120B (trade name of Rohm and Haas), Diaion SK-1A (trade name of Mitsubishi Chemical Corporation), Diaion FMK-10 (Mitsubishi Chemical Corporation)
(Trade name).

Examples of the weakly acidic cation exchange resin include those having a base material such as a copolymer of acrylate or methacrylate and divinylbenzene and having a carboxyl group or a phosphone group as an ion exchange group. These are, for example, Amberlite IRC-84 (ROHM
And Haas Co., Ltd.), Diaion WK-11
(Trade name of Mitsubishi Chemical Corporation).

The anion exchange resin includes a strongly basic anion exchange resin and a weakly basic anion exchange resin, and any anion exchange resin can be used in the present invention.

As a strong basic anion exchange resin, for example, a styrene-divinylbenzene copolymer or the like is used as a base, and a trimethylammonium group, β
Those having a hydroxyethyldimethylammonium group. These include, for example, Amberlite IRA-400 (trade name of Rohm and Haas), Diaion SA-10B (trade name of Mitsubishi Chemical Corporation), Diaion FMA-10 (trade name of Mitsubishi Chemical Corporation) It is commercially available.

The weakly basic anion exchange resin is based on, for example, a styrene-divinylbenzene copolymer, a copolymer of acrylate or methacrylate and divinylbenzene, and has primary, secondary and tertiary amino groups as ion exchange groups. And the like. These are, for example, Amberlite IRA-410 (ROHM &
It is commercially available as Haas Co., Ltd.) and Diaion FA-20B (trade name of Mitsubishi Chemical Corporation).

Inorganic ion exchange materials which are another ion exchange material usable in the present invention include cation exchange materials and anion exchange materials.

Examples of the cation-exchanger include polyvalent metal acids such as zeolite, antimonic acid, stannic acid, titanic acid, niobic acid and manganic acid and salts thereof; zirconium phosphate, titanium phosphate, tin phosphate And polybasic metal salts such as cerium phosphate, tin arsenate and titanium arsenate; and heteropoly acids such as molybdic acid and tungstic acid.

Examples of the anion exchangeable inorganic substance include hydrotalcite, hydroxyapatite, hydrated oxides such as hydrated iron oxide, hydrated zirconium hydroxide and hydrated bismuth oxide.

These ion-exchange materials can be used alone or in combination depending on the type of electrolyte to be captured.

There are a wide variety of electrolytes that cause corrosion. The mechanism of corrosion by the electrolyte is presumed to be due to the movement of the dissociated electrolyte ions as described above. Therefore, it is preferable to select an ion-exchange material to be used in accordance with the type of electrolyte, the degree of dissociation, and the ionic strength to which adhesion is expected. Hereinafter, the use form of the ion exchange material and the type of the electrolyte will be described, but the present invention is not limited thereto.

(1) An embodiment in which a cation exchange material and an anion exchange material are used together This embodiment is suitable when the electrolyte is a salt. Examples of such an electrolyte include a salt of a strong acid and a strong base, and specific examples thereof include, for example, NaCl, NaB
r, NaI, Na ₂ SO ₄ , NaNO _{3 and the} like. Hydrogen ions and hydroxyl ions generated by ion exchange are recombined to form water. This water does not corrode because it has high electrical resistance and is removed by drying.

A particularly preferred combination is a strongly acidic cation exchange resin and a strongly basic anion exchange resin in view of ion exchange rate and ion exchange capacity. A combination of a resin, a weakly acidic cation exchange resin and a strongly basic anion exchange resin, or a weakly acidic cation exchange resin and a weakly basic anion exchange resin is also possible.

The target electrolyte is not limited to the salt of the strong acid and the strong base, but may be (NH ₄ ) ₂ SO ₄ , NH ₄ Cl, or Al.
Salt of a strong acid such as ₂ (SO ₄ ) ₃ with a weak base, Na ₂ CO ₃ ,
Salts of strong bases and weak acids such as K ₂ CO ₃ and NaHCO ₃ , (N
The present invention is also applicable to a salt of a weak acid and a weak base such as H ₄ ) ₃ PO ₄ , (NH ₄ ) ₃ AsO ₄ , and FeAsO ₄ .

The use ratio of the cation exchange material and the anion exchange material may be selected depending on the type of the target electrolyte and the type of the ion exchange material. Exchangeable material (weight ratio)
Is preferably in the range of about 9/1 to 1/9, and more preferably about 2/1 to 1/2, in that it can correspond to any electrolyte.

When the electrolyte is a salt of a strong acid and a strong base, the amount of the electrolyte is around an equal amount, and when the electrolyte is a salt of a strong base and a weak acid, the amount of the cation-exchange material is larger than that of the electrolyte. In such a case, it is preferable to increase the amount of the anion exchangeable material.

(2) Embodiment in which the cation exchange material is used alone This embodiment is suitable when the electrolyte is a base.
For example, hydroxides of alkali metals such as Na, K, and Li; hydroxides of alkaline earth metals such as Mg and Ca; aqueous ammonia and hydroxides of secondary, tertiary, and quaternary ammoniums.

The present invention can also be effectively applied when the electrolyte is a salt of a strong base and a weak acid or a salt of a weak base and a weak acid.

As the cation exchange material to be used, any of the above-mentioned materials can be used, but ion exchange resins are preferred from the viewpoint of specific gravity, and in particular, from the viewpoints of ion exchange rate and ion exchange capacity, strongly acidic cation exchange materials. Resins are preferred. From the viewpoint of heat resistance, an inorganic cation exchange material is preferred.

(3) Embodiment in which an anion-exchange material is used alone This embodiment is suitable for an acid. Examples of such substances include inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, and phosphoric acid, and organic acids such as formic acid, acetic acid, propionic acid, and phthalic acid.

The present invention can also be effectively applied when the electrolyte is a salt of a strong acid and a weak base or a salt of a weak acid and a weak base.

As the anion-exchange material to be used, any of the above-mentioned ones can be used, but an ion-exchange resin is preferable from the viewpoint of specific gravity, and particularly, a strongly basic anion-exchange resin from the viewpoint of ion-exchange speed and ion-exchange capacity. Resins are preferred. In addition, an inorganic anion exchangeable substance is preferable from the viewpoint of heat resistance.

The combination of ion-exchange materials has been exemplified above, but a combination of two or more cation-exchange materials and a combination of two or more anion-exchange materials are also possible.

The combined use of a cation exchange material and an anion exchange material is advantageous in that it can be applied to any type of electrolyte. On the other hand, when used alone, the width of the target electrolyte is reduced, but the target ion is increased by increasing the blending amount of the ion-exchange material suitable for the ions to be captured without changing the total amount of the ion-exchange material. This is advantageous in that the trapping amount can be increased.

The coating material of the present invention can be obtained basically by mixing the above-mentioned film forming agent and the ion exchange material in the presence or absence of a solvent.

As the solvent, either water or an organic solvent can be used, and it may be appropriately selected according to the type of the film forming agent to be used.

For example, when the above-mentioned hydrophilic film forming agent is used, water or a hydrophilic organic solvent can be used alone or as a mixture (in this specification, this type of coating is sometimes referred to as “aqueous coating”). . In this case, it is advantageous in that the electrolyte is easily dissolved.

Examples of the hydrophilic organic solvent include alcohols such as methanol, ethanol and isopropanol; cellosolves such as methyl cellosolve, ethyl cellosolve and butyl cellosolve; ethers such as tetrahydrofuran and dioxane;
Species or more, but not limited to.

As a solvent when the above-mentioned hydrophobic film forming agent is used, a hydrophobic organic solvent is preferable. Examples of the hydrophobic organic solvent include benzene, toluene, xylene,
Examples include, but are not limited to, hydrocarbons such as thinners; esters such as methyl acetate and ethyl acetate; and ketones such as methyl ethyl ketone and methyl isobutyl ketone. In this case, it is advantageous in that the obtained paint has a high drying speed.

Note that depending on the type of the film forming agent,
A mixed solvent of a combination of a water-hydrophilic organic solvent, a water-hydrophobic organic solvent (emulsion system), and a hydrophilic organic solvent-hydrophobic organic solvent can also be used.

The paint in the present invention may be a solvent-free paint. Examples of the film-forming agent used in this case include those conventionally used in solvent-free paints, such as epoxy resins, urethane resins, unsaturated polyester resins, and silicone resins. In this case,
This is advantageous in that no ventilation equipment is required.

The ion-exchange material to be mixed can be used in the form of granules, fibers, scales, pellets, etc., but granules are preferred from the viewpoint of dispersibility. In that case, the particle size is not particularly limited, but uniformity of dispersion and ease of application,
In terms of specific surface area and the like, the average particle size is about 1000 μm or less,
It is preferably about 1 to 1000 μm.

The amount of the ion exchange material used depends on the type of the ion exchange material, the type and amount of the electrolyte, the degree of dissociation, the ionic strength, and the like.
It is used in a range occupying 2 to 99.8% by weight. Preferably, it is 20 to 80% by weight.

Various additives can be added to the coating composition of the present invention as long as the ion exchange capacity of the ion exchange material is not reduced and the corrosion prevention performance is not impaired. Examples of the additive include a coloring agent, an organic or inorganic filler, an anti-settling agent, an anti-cissing agent and the like. When a coloring agent is added among these, the range of application is clear, and workability is improved.

The coating composition of the present invention is prepared by appropriately mixing the above components according to a conventional method. The form may be a dispersion, suspension, emulsion, slurry, or paste, and may be selected according to the method of application.

The method for applying the coating material obtained as described above to an oxide semiconductor is not particularly limited as long as it is a conventional method. For example, a brush coating method, a brush coating method,
Spray method, dipping method, roll method, curtain flow method and the like can be mentioned. After coating by such a method, it may be dried by a method such as natural drying to form a coating film.

[0093] When the coating is applied to the oxide semiconductor, it is preferable to apply the coating to at least a portion that can be exposed to the atmospheric environment, as described later in detail. In the case where a metal film is stacked on the surface of the oxide semiconductor for reducing wiring resistance, the metal film may be applied to a portion of the surface of the metal film which can be exposed to the air environment.

The thickness of the obtained coating film may be appropriately selected within a wide range according to the type and content of the film forming agent. However, it should be noted that if the thickness is too thick, the drying becomes slow and the adhesiveness may be poor. On the other hand, if it is too thin, coating defects such as pinholes are likely to occur. In the present invention, even if a pinhole or the like is generated and the electrolytic solution reaches the oxide semiconductor, the oxide semiconductor does not corrode due to the presence of the ion-exchange material. From the viewpoints of workability and corrosion prevention effect, the thickness of the coating film may be in the range of 1 μm to 1 mm.

As described above, the present invention also relates to a method for preventing corrosion of an oxide semiconductor, which comprises applying a film-forming agent and an ion-exchange material to the surface of the oxide semiconductor.

The oxide semiconductor to which the coating for preventing corrosion of an oxide semiconductor of the present invention has been applied can be used for, for example, electrochromic displays, dimming devices, solar cells, optical switches, automobiles, cameras, etc. Heaters, panel heaters for heating, meter indicator windows, cathode ray tube display surfaces, outer lamps, solar collectors, etc.

In particular, when manufacturing a liquid crystal display device, a substrate, a liquid crystal, an alignment film, and a metal film (for example, Cr, Al, C
u, Ni and alloys containing these as main components), and an oxide semiconductor which has been subjected to the above-described corrosion prevention treatment, can be manufactured by a conventional method. In this case, the oxide semiconductor is preferably ITO, ATO, or AZO from the viewpoint of high transmittance and high durability. Further, from the viewpoint of improving the workability of application and the effect of preventing corrosion, after sealing the liquid crystal between the substrates using a sealing member, the paint containing a film forming agent and an ion exchange material is applied to the substrate. It is preferable to manufacture it.

Here, the liquid crystal display device is shown in FIGS. 1 to 5 in an embodiment in which the paint is applied to an oxide semiconductor in order to perform a corrosion prevention treatment according to the present invention. 1 to 5 are partial schematic cross-sectional views of a liquid crystal display device subjected to a corrosion prevention process according to the present invention. 1A, 1a is an upper substrate, 1b is a lower substrate, 2a is an upper transparent conductive film (oxide semiconductor), 2b is a lower transparent conductive film, 3a is an upper alignment film, 3a
b is a lower alignment film, 4 is a liquid crystal, 5 is a seal member, 6 is a coating film formed by applying the paint of the present invention, 7 is a metal film, 8 is a connection portion, and 9 is a driving circuit board.

In the embodiment 1 shown in FIG. 1, the coating film 6 is provided on the surface of the lower transparent conductive film 2b which can be exposed to the air environment and on the end of the metal film 7. In this case, the alignment film 3a,
Since a coating film is provided on the lower conductive film 2b electrically connecting the liquid crystal substrate including the liquid crystal 4 and the sealing member 5 to the driving circuit board 9, conduction failure and disconnection due to corrosion are prevented. preferable. Further, it is preferable in that current leakage from the metal film 7 to the lower transparent conductive film 2b via the electrolytic solution can be prevented.

In the embodiment 2 shown in FIG. 2, in addition to the surface of the lower transparent conductive film 2b and the end of the metal film 7 which can be exposed to the air environment, the end of the connection portion 8 and the drive circuit board 9
Is also provided with a coating film 6 at the end. In this case, the connecting part 8
Even if the electrolyte adheres to the end of the circuit board 9 and the end of the drive circuit board 9, it is also possible to prevent a current leak from the connection section 8 and the drive circuit board 9 to the transparent conductive film 2b via the electrolyte. This is preferable in that respect.

In Embodiment 3 shown in FIG. 3, in addition to the surface of the lower transparent conductive film 2b provided with the coating film in FIG. 1 and the end of the metal film 7, the upper transparent conductive film 2 formed on the upper substrate 1a is formed.
The coating film 6 is also provided on the part of the seal member 5 that can be exposed to the atmosphere environment of a. In this case, the sealing member 5
This is preferred in that even if the electrolyte adheres to the surface of the substrate, current leakage between the upper transparent conductive film 2a and the lower transparent conductive film 2b through the electrolyte can be prevented.

Embodiment 4 shown in FIG. 4 is a combination of Embodiments 1 to 3. In this case, prevention of current leak from the metal film 7 to the lower transparent conductive film 2b via the electrolytic solution, and prevention of current leak from the connection portion 8 and the driving circuit board 9 to the lower transparent conductive film 2b through the electrolytic solution. This is preferable in terms of prevention and prevention of current leak between the upper transparent conductive film 2a and the lower transparent conductive film 2b via the electrolytic solution.

In the embodiment 5 shown in FIG. 5, when the metal film 7 extends to reduce the wiring resistance in the embodiment 4 shown in FIG.
The coating film 6 is also provided on the extended portion of the. In this case,
This is preferable from the viewpoint of preventing corrosion of the metal film 7 as well as the lower transparent conductive film 2b.

In the case of manufacturing a heater for anti-fogging and frost, it can be manufactured by a conventional method by using a substrate, a metal film, and an oxide semiconductor which has been subjected to the above-described corrosion prevention treatment. Also in this case, the oxide semiconductor is preferably ITO, ATO, or AZO.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto.

[0106]

EXAMPLES Example 1 A strongly acidic cation exchange resin having a cation exchange functional group as a sulfonic acid group was added to an aqueous acrylic resin paint (polished varnish manufactured by Atomics Co., Ltd.) having the following composition. Strongly basic anion exchange resin (Diaion FMK-10 manufactured by Mitsubishi Chemical Co., Ltd.) having a quaternary ammonium group as a functional group having an anion exchange capability with Diaion FMK-10 manufactured by Mitsubishi Chemical Corporation Was used as the paint of the present invention. Each ion exchange resin had an average particle size of about 100 μm. The solid content of this paint was mixed so that the strongly acidic cation exchange resin was 25% by weight and the strongly basic anion exchange resin was 25% by weight.

Using this coating material, a coating film 6 was formed on the surface of the lower transparent conductive film 2b (here, ITO was used) of the liquid crystal display device as shown in FIG. Then, by driving the liquid crystal display device After a 0.1N-Na ₂ SO ₄ aqueous solution on the coating film 6 was dropped using a dropper, whether conduction failure occurs, and in the lower substrate 1b (here, glass Was used)
The lower transparent conductive film 2b was visually observed from the back surface to determine whether or not the lower transparent conductive film 2b was corroded, and the corrosion prevention performance was evaluated. As a result, no conduction failure occurred, and the lower transparent conductive film 2b
Was not corroded.

Aqueous coating composition (% by weight) Water-soluble acrylic resin 35 Ethyl cellosolve 35-40 Butyl cellosolve 5-10 Isopropyl alcohol 20-30 Total 100

Examples 2 to 4 Water-based paints were prepared using acrylic emulsions (Acrose # 100V manufactured by Dainippon Paint Co., Ltd.) and vinyl chloride emulsions (vinylose # 41 manufactured by Dainippon Paint Co., Ltd.)
0) or an acrylic water-based paint (Buetex manufactured by Dainippon Paint Co., Ltd.), and a paint was produced and evaluated in the same manner as in Example 1. As a result, no conduction failure occurred, and the lower transparent conductive film 2b was not formed.
Was not corroded.

Example 5 Organic solvent-based paint of polyolefin resin having the following composition (HumiSeal-1B manufactured by AR BROWN)
51), 25% by weight of a strongly acidic cation exchange resin (Diaion FMK-10 manufactured by Mitsubishi Chemical Corporation) and a strongly basic anion exchange resin (Diaion F manufactured by Mitsubishi Chemical Corporation)
MA-10) was used as a coating. This coating material was applied in the same manner as in Example 1, and the corrosion prevention performance was evaluated. As a result, no conduction failure occurred, and the lower transparent conductive film 2b was not corroded.

Organic solvent-based coating composition (% by weight) Modified polyethylene 20-30 Toluene 70-80 Total 100

Examples 6 to 10 As organic solvent-based coatings, alkyd resin (Merami No. 51 manufactured by NOF Corporation), urea melamine resin (Meramix 1230 manufactured by Nippon Paint Co., Ltd.), epoxy resin Nippon Paint Co., Ltd. Eponics # 10),
Polyester resin (3200V manufactured by Nippon Paint Co., Ltd.)
Clear), acrylic resin (Nippe Acrylic manufactured by Nippon Paint Co., Ltd.), vinyl resin (Vinylex 2000 manufactured by Nippon Paint Co., Ltd.), or urethane resin (V top H overcoat manufactured by Dainippon Paint Co., Ltd.) A coating material was produced and evaluated in the same manner as in Example 5, except for using it. As a result, no conduction failure occurred, and the lower transparent conductive film 2b was not corroded.

Example 11 A room-temperature-curable silicone rubber (KE3420 manufactured by Shin-Etsu Chemical Co., Ltd.) was used as a film forming agent, and a strongly acidic cation exchange resin (Diaion FM manufactured by Mitsubishi Chemical Corporation) was used.
K-10) and a strongly basic anion exchange resin (Diaion FMA-10 manufactured by Mitsubishi Chemical Corporation) were mixed to obtain a paint.

The solid content of the coating composition was 50% by weight of a room temperature-curable silicone rubber, 25% by weight of a cation exchange resin, and 25% by weight of an anion exchange resin. Each of the ion exchange resins had an average particle size of about 100 μm, and the thickness of the coating film was about 1 μm. Then, the corrosion prevention performance was evaluated in the same manner as in Example 1. As a result, no conduction failure occurred, and the lower transparent conductive film 2b was not corroded.

Examples 12 to 20 As a film forming agent, an ultraviolet-curable silicone rubber (KE4830 manufactured by Shin-Etsu Chemical Co., Ltd.), a moisture-curable urethane resin (Tourethane MC clear manufactured by Tove Co., Ltd.), a solvent-free speed Dry silicone (SE9187L manufactured by Dow Corning Toray Silicone Co., Ltd.), UV-curable silicone (V549 manufactured by Ryoden Kasei Co., Ltd.), epoxy resin (ARADITE CY23 manufactured by Chiba Nagase Co., Ltd.)
0), natural rubber adhesive (PAPER manufactured by KOKUYO Co., Ltd.)
BOND), acrylic resin emulsion-based adhesive (marker glue manufactured by Konishi Co., Ltd.), animal-based adhesive (Nika),
Example 1 except that a vegetable adhesive (starch paste) was used.
A paint was manufactured and evaluated in the same manner as described above. As a result, no conduction failure occurred, and the lower transparent conductive film 2b was not corroded.

Example 21 Corrosion of a transparent conductive film when an aqueous paint (polish varnish manufactured by Atomics Co., Ltd.) was used as a film forming agent and antimony hydroxide as an inorganic ion exchange material was used as an ion exchange material. The prevention effect was investigated. The solid content composition of the paint was 50% by weight of the aqueous paint and 50% by weight of hydrous antimony oxide (inorganic ion exchange material). As a result, no conduction failure occurs and the lower transparent conductive film (for example, ITO)
2b was not corroded.

Examples 22 to 24 As an ion-exchange material, zirconium phosphate, hydrotalcite or hydroxyapatite was replaced with hydrous antimony as an inorganic ion-exchange material. A coating composition of the present invention was prepared in the same manner as in Example 21 by weight and evaluated. As a result, no conduction failure occurred, and the lower transparent conductive film 2b was not corroded.

Examples 25 to 28 Organic solvent-based paints (AR BRO) instead of water-based paints
A coating material was manufactured and evaluated in the same manner as in Examples 21 to 24, except that HumiSeal-1B51 manufactured by WN was used. As a result, no conduction failure occurred, and the lower transparent conductive film 2b was not corroded.

Embodiments 29 to 56 First, FIG. 6 is a schematic sectional view of a heater for anti-fog and frost prepared in this embodiment. In FIG. 6, 10 is a substrate (for example, glass), 11 is an oxide semiconductor (for example, ITO), 12 is a metal film (for example, Ag), and 13 is a coating film obtained by applying the paint of the present invention. is there.

As shown in FIG. 6, using one of the paints obtained in Examples 1 to 28, the transparent conductive film 11 and the metal film 1 were used.
2 and the surface portion of the metal film 12 were applied by brushing and dried by standing naturally to form a coating film. The reason why the coating film is formed on such a portion is that if pinholes or the like are present at the boundary portion and the surface portion, the moisture in the atmosphere is condensed due to a capillary condensation phenomenon, and an electrolytic solution can be generated.

With respect to the anti-fogging and defrosting heater obtained as described above, a 0.1N-Na ₂ SO ₄ aqueous solution was dropped on the coating film 13 by using a dropper, and 10
The anti-corrosion performance was evaluated by applying a direct current of 0 V to determine whether or not conduction failure occurred, and whether or not the substrate 10 was corroded by visual observation from the back surface of the substrate 10. As a result, no conduction failure occurred, and the oxide semiconductor 11 was not corroded.

[0122]

According to the first aspect of the present invention, a film-forming agent serving to hold an ion-exchangeable material on the surface of an oxide semiconductor, a salt contained in sea salt particles and dust (electrolyte)
Since it is a paint composed of an ion-exchange material that traps and removes, it has an effect of preventing corrosion of the oxide semiconductor.

According to the second aspect of the present invention, since the film forming agent is hydrophilic, an effect of easily capturing and removing the electrolyte (ions) contained in the electrolytic solution can be obtained.

According to the third aspect of the present invention, since an easily available resin is used as the hydrophilic film forming agent, an effect of easily producing an oxide semiconductor corrosion preventing paint can be obtained.

According to the fourth aspect of the present invention, water and / or
Alternatively, since the hydrophilic organic solvent is used as the solvent, the hydrophilic film forming agent and the ion exchange material can be uniformly dispersed and mixed, and the effect of effectively removing the electrolyte can be obtained.

According to the fifth aspect of the present invention, since the film forming agent is hydrophobic, the drying speed is high and the workability of coating is improved.

According to the sixth aspect of the present invention, an easily available resin is used as the hydrophobic film forming agent, so that an effect of easily forming an oxide semiconductor corrosion preventing coating can be obtained.

According to the seventh aspect of the present invention, since the hydrophobic organic solvent is used as the solvent, the hydrophobic film forming agent and the ion exchange material can be uniformly dispersed and mixed, and the effect of effectively removing the electrolyte can be obtained. .

According to the eighth aspect of the invention, when a solvent is used, there is an effect that the film forming agent and the ion exchange material can be uniformly dispersed and mixed. If no solvent is used, there is an effect that ventilation equipment is unnecessary.

According to the ninth aspect of the present invention, since a film forming agent does not use a solvent, an effect that ventilation equipment is not required is exhibited.

According to the tenth aspect of the present invention, since an adhesive, a sealant, and a pressure-sensitive adhesive used in fields other than paints are used as a film-forming agent, they are easily available and easily prevent oxide semiconductor corrosion. This has the effect of producing a paint.

According to the eleventh aspect of the present invention, since the ion-exchangeable material is an ion-exchange resin, there is an effect that the electrolyte (ions) in the electrolytic solution can be captured and removed.

According to the twelfth aspect of the present invention, the ion exchange resin is at least one selected from the group consisting of a cation exchange resin and an anion exchange resin. The exchange resin and the anion exchange resin can capture and remove anions in the electrolyte solution.

According to the thirteenth aspect, since the cation exchange resin is a strongly acidic cation exchange resin, the cation exchange rate is high and the cation exchange capacity is large. Therefore, an effect is obtained that cations in the electrolytic solution can be quickly captured and removed.

According to the invention of claim 14, since the anion exchange resin is a strongly basic anion exchange resin, the anion exchange rate is high and the anion exchange capacity is large. Therefore, an effect is obtained that anions in the electrolytic solution can be quickly captured and removed.

According to the fifteenth aspect, since the ion-exchange material is an inorganic ion-exchange material, it has an excellent heat resistance.

According to the sixteenth aspect of the present invention, since an easily available inorganic ion-exchange substance is used as the ion-exchange material, there is an effect that an oxide semiconductor corrosion preventing paint can be easily produced.

According to the seventeenth aspect of the present invention, the content of the ion-exchange material is 0.2 to 99.8% by weight of the solid content, so that the content of the ion-exchange material can be selected over a wide range according to the use environment. To play.

According to the eighteenth aspect of the present invention, since the ion exchange material is granular and has an average particle size of 1 to 1000 μm, it can have a large specific surface area and can be uniformly dispersed in a coating film. Thereby, there is an effect that the electrolyte (ions) can be efficiently removed.

According to the nineteenth aspect of the present invention, since a paint containing a film forming agent and an ion-exchange material is applied to the surface of the oxide semiconductor, the electrolyte in the electrolyte adhering to the surface of the oxide semiconductor is coated. (Ion) can be captured and removed by the ion exchange material. Thus, an effect of preventing corrosion of the oxide semiconductor can be obtained.

According to the twentieth aspect, a paint containing a film forming agent and an ion-exchange material is applied to the surface of the oxide semiconductor used for the liquid crystal display device. The electrolyte (ions) in the electrolyte solution obtained can be captured and removed by the ion exchange material. Accordingly, the effect of preventing corrosion of the oxide semiconductor and preventing an increase in resistance and disconnection failure of the liquid crystal display device can be obtained.

According to the twenty-first aspect of the present invention, a paint containing a film-forming agent and an ion-exchange material is applied to the surface of an oxide semiconductor exposed to the atmospheric environment used for a liquid crystal display device. An electrolyte (ion) in the electrolyte solution attached to the surface of the semiconductor can be captured and removed by the ion exchange material. Accordingly, the effect of preventing corrosion of the oxide semiconductor and preventing an increase in resistance and disconnection failure of the liquid crystal display device can be obtained. In addition, a paint containing a film-forming agent and an ion-exchange material is applied to the surface of a metal film formed on an oxide semiconductor exposed to the air environment used for a liquid crystal display device to reduce wiring resistance. Therefore, the electrolyte (ions) in the electrolyte attached to the surface of the metal film is captured by the ion exchange material.
Can be removed. Accordingly, corrosion of the metal film and the oxide semiconductor can be prevented, and an effect of preventing an increase in resistance and disconnection failure of the liquid crystal display device can be obtained.

According to the invention of claim 22, since a paint containing a film forming agent and an ion-exchange material is applied to the surface of the seal member used for the liquid crystal display device, the liquid crystal display device is driven. Even if the electrolyte adheres to the surface of the seal member existing between the upper oxide semiconductor (transparent conductive film) and the lower oxide semiconductor (transparent conductive film), no current leaks through the electrolyte. Accordingly, the effect of preventing corrosion of the oxide semiconductor and preventing an increase in resistance and disconnection failure of the liquid crystal display device can be obtained.

According to the twenty-third aspect of the present invention, a material containing a film forming agent and an ion-exchange material is applied to the surface of the oxide semiconductor used for the heater for anti-fogging and defrosting. The electrolyte (ion) in the electrolytic solution adhered to the ion exchange material can be captured and removed. Thereby, corrosion of the oxide semiconductor can be prevented, and an effect of preventing an increase in resistance and a disconnection failure of the heater for anti-fog and defrost can be achieved.

According to the twenty-fourth aspect, a paint containing a film forming agent and an ion-exchange material is applied to the surface of the oxide semiconductor used for the anti-fog and defrost heater.
Electrolyte (ions) in the electrolytic solution attached to the surface of the oxide semiconductor can be captured and removed by the ion-exchange material. In addition, since a paint containing a film forming agent and an ion-exchange material is applied to the surface of the metal film formed on the oxide semiconductor, the electrolyte (ion) in the electrolytic solution attached to the surface of the metal film is ion-exchangeable. Can be captured and removed by material. Accordingly, corrosion of the metal film and the oxide semiconductor can be prevented, and an effect of preventing an increase in resistance and a disconnection failure of the anti-fog and frost heater can be obtained.

[Brief description of the drawings]

FIG. 1 is a partial schematic cross-sectional view of a liquid crystal display device subjected to a corrosion prevention process according to the present invention.

FIG. 2 is a partial schematic cross-sectional view of a liquid crystal display device that has been subjected to a corrosion prevention process according to the present invention.

FIG. 3 is a partial schematic cross-sectional view of a liquid crystal display device that has been subjected to a corrosion prevention process according to the present invention.

FIG. 4 is a partial schematic cross-sectional view of a liquid crystal display device that has been subjected to a corrosion prevention process according to the present invention.

FIG. 5 is a partial schematic cross-sectional view of a liquid crystal display device that has been subjected to a corrosion prevention process according to the present invention.

FIG. 6 is a schematic cross-sectional view of a heater for anti-fog and defrost prepared in an example of the present invention.

FIG. 7 is a schematic diagram for explaining the corrosion mechanism of ATO.

FIG. 8 is a partial schematic cross-sectional view of a conventional liquid crystal display device.

[Explanation of symbols]

1 substrate, 2 transparent conductive film, 3 alignment film, 4 liquid crystal, 5
Sealing member, 6 paint film, 7 metal film, 8 connection part, 9
Driving circuit board, 10 substrate, 11 transparent conductive film, 12
Metal film, 13 coatings, 20 power supply, 21 Ag anode,
22 Ag cathode, 23 ATO, 24 glass substrate, 2
5 droplet, 26 current, 27 anode part, 28 cathode part, 29 moving width, 30 corroded part.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tadao Nishimori 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsubishi Electric Co., Ltd. Company Advanced Display

Claims (24)

[Claims] 1. A paint for preventing corrosion of an oxide semiconductor, comprising a film-forming agent and an ion-exchange material. 2. The coating composition according to claim 1, wherein the film forming agent is a hydrophilic film forming agent. 3. The method according to claim 1, wherein the hydrophilic film forming agent is an acrylic resin having a hydrophilic group, an alkyd resin, a melamine resin, a urea resin, a phenol resin, an epoxy resin, a cellulose resin.
The paint according to claim 2, which is a urethane resin, a polyacetal resin, a polyvinyl alcohol resin or a vinyl chloride resin. 4. The coating according to claim 2, wherein water and / or a hydrophilic organic solvent is used as a solvent. 5. The coating according to claim 1, wherein the film forming agent is a hydrophobic film forming agent. 6. The hydrophobic film forming agent is a cellulose resin, alkyd resin, melamine resin, urea resin, vinyl chloride resin, butyral resin, aminoalkyd resin, acrylic resin, epoxy resin, unsaturated polyester resin, urethane resin, olefin resin. 6. The paint according to claim 5, which is a vinyl acetate resin. 7. The coating according to claim 5, wherein a hydrophobic organic solvent is used as a solvent. 8. The coating according to claim 1, which contains or does not contain a solvent. 9. The coating composition according to claim 1, which contains no solvent and wherein the film-forming agent is an epoxy resin, a urethane resin, an unsaturated polyester resin or a silicone resin. 10. The film-forming agent is chloroprene rubber,
The paint according to claim 1, which is a nitrile rubber, a styrene-butadiene rubber, a silicone rubber, a poly-n-butyl acrylate, glue or starch paste. 11. The coating according to claim 1, wherein the ion exchange material is an ion exchange resin. 12. The paint according to claim 11, wherein the ion exchange resin is at least one selected from the group consisting of a cation exchange resin and an anion exchange resin. 13. The coating according to claim 12, wherein the cation exchange resin is a strongly acidic cation exchange resin. 14. The coating according to claim 12, wherein the anion exchange resin is a strongly basic anion exchange resin. 15. The coating according to claim 1, wherein the ion exchange material is an inorganic ion exchange substance. 16. The coating according to claim 15, wherein the inorganic ion exchangeable substance is one selected from the group consisting of antimony hydroxide, zirconium phosphate, hydrosaltite and hydroxyapatite. 17. The coating according to claim 1, wherein the ion-exchangeable material is 0.2 to 99.8% by weight of the solid content of the coating. 18. The coating material according to claim 1, wherein the ion-exchange material is granular and has an average particle size of 1 to 1000 μm. 19. A method for preventing corrosion of an oxide semiconductor, comprising applying a paint containing a film-forming agent and an ion-exchange material to a surface of the oxide semiconductor. 20. A liquid crystal display device comprising an oxide semiconductor formed by applying the paint according to claim 1. 21. A paint is applied to a surface of an oxide semiconductor which is exposed to the air environment or a surface of a metal film formed on a surface of the oxide semiconductor which is exposed to the air environment. The liquid crystal display device according to claim 20, wherein: 22. The liquid crystal display device according to claim 21, wherein the liquid crystal is sealed between the substrates by using a sealing member, and the paint is applied to the surface of the substrate or the substrate and the sealing member. 23. An anti-fogging and defrosting heater comprising an oxide semiconductor obtained by applying the paint according to claim 1. 24. The coating material is applied to a surface of an oxide semiconductor which is exposed to the air environment or a surface of a metal film formed on the surface of the oxide semiconductor which is exposed to the air environment. 24. The heater for anti-fog and defrost according to claim 23.