JPH02169685A - Transparent, conductive ultraviolet-absorbing material and its manufacture - Google Patents

Abstract

PURPOSE:To obtain a transparent, conductive ultraviolet-absorbing material at low cost by dissolving a mixture of an acidic salt of zinc with a tin- containing doping agent at a specified molar ratio in water, neutralizing the solution, washing the precipitate and separating it by filtration, followed by heat treatment at a specified temperature. CONSTITUTION:An acidic salt of zinc (e.g. zinc sulfate or zinc chloride) is mixed with a tin-containing doping agent (e.g. tin sulfate) so as to provide a molar ratio of zinc to tin of 100:(0.02 to 5). This mixture is dossolved in water to give a concentration in terms of zinc oxide of 7wt.% or less. This solution is neutralized with a solution of an alkali (e.g. sodium carbonate). The precipitate produced in the solution is washed and separated by filtration, and then heated to 400-700 deg.C, thus giving a transparent, conductive ultraviolet-absorbing material. The powder of this material is mixed with, e.g. a solvent, and this mixture is applied to a base plate, dried, and heated at 200-400 deg.C in a reducing atmosphere, giving a transparent, conductive ultraviolet-screening thin film.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing a transparent conductive ultraviolet absorbing material. In particular, the present invention relates to a method for producing a coating material that requires conductivity, transparency, and UV blocking, and a method for producing a transparent conductive ultraviolet m blocking thin film using the same.

[Prior art and problems to be solved by the invention] In general, as transparent conductive materials, antimony-doped tin oxide (ATO) and tin-doped indium (ITO) are formed into thin films by MP or sputtering using the JJ method. However, due to the necessity of processing in a vacuum and the difficulty in making the processing process continuous, the equipment becomes expensive and large, and it is difficult to prepare large-area thin films. , it becomes impossible due to the equipment. However, if the desired shape of the thin film is complex, shadows will occur during sputtering, etc., making the film unusable.

However, recently it has become desirable to apply a film using conductive paint.
, conductive paints containing ATO or ITO as fillers are commercially available.

Furthermore, since the organic antistatic agent has ionic conductivity, its conductivity varies greatly depending on the humidity of the atmosphere.

In addition, it often leaks onto the surface of the membrane, which poses a hygiene problem.

Another method is to coat the surface with ethyl silicate and utilize the conductivity of silanol groups (S i OH), but it is also strongly affected by humidity and loses its conductivity when dry. There is.

Conventionally, organic substances, titania, and zinc oxide have been used as transparent UV blockers;
It absorbs ultraviolet rays, degrades itself, changes color, turns from yellow to brown, and eventually loses its ability to absorb ultraviolet rays, which also poses a hygiene problem.

The ultraviolet blocking ability of titania is + if it is a rutile type.
Since it blocks up to the 1f visible light range, it has a yellowish tinge. In the case of the anatase type, it absorbs ultraviolet rays in the region below 350n-, but does not absorb the part between 350 and 400n-. However, the part of the ultraviolet rays between 350 and 400rs- is extremely harmful. Generally, 35
There is a need for materials that also absorb ultraviolet rays in the 0n- or higher ultraviolet range. In addition, titania is the most pure white pigment, so the titania UV blockers on the market whiten.
Transparency is quite low.

The ultraviolet blocking ability of titania -A is due to its high refractive index, so the ultraviolet rays that enter the titania particles also go out of the particles, so the effect of ultraviolet rays around the particles Y is reduced by 2 This results in twice as much damage, and the deterioration of surrounding organic matter increases. In addition, zinc oxide's ability to block ultraviolet rays is due to electric r-absorption, and although it blocks the region below 380n-, there is a strong demand for it to block ultraviolet rays closer to 400n+s.Zinc oxide sharply blocks ultraviolet rays. I'I
Since the blocking hem does not extend to the f-visual region, it does not give any color, but zinc oxide is classified as a white pigment and is white, so conventionally, it has been used as a UV absorbing agent in tanning IL lotions for chemical 1E. Although it is only used in
Even in this case, it will become too white, so add other pigments,
It cannot be used unless it is treated to have a color similar to skin color.

For both the transparent conductive filler and the transparent ultraviolet blocking filler, it is not preferable to use an organic substance for the above-mentioned reasons, but if the filler is an inorganic substance, a powder filler will be used. When the particle size becomes larger than the wavelength of visible light, the particle size absorbs light and becomes opaque. Over time, the price of powder becomes extremely high. In order to obtain a film having the dual properties of transparent conductivity and transparent ultraviolet light blocking, the expensive film must be coated twice. In particular, when applying by spray or spinner, the paint loss rate is as high as 99.9%.
Therefore, it is desired to create a film that exhibits two properties with one coating, but conventional methods require a conductive filler and ultraviolet blocking coating. It is conceivable to mix both fillers into the same paint, but in the case of conductive fillers, it is best to mix the filler as much as possible so that the fillers connect with each other and have conductivity. Since it is common, there is no room for adding an ultraviolet blocking filler, so it is desired that a film having two properties can be obtained by applying a single filler.

Also, if zinc oxide is doped with aluminum, gallium, indium, germanium, or tin, the volume resistivity increases by 10
-'-10"ΩC-.In the conventional doping method, a heat treatment is performed at a temperature of 600 to 900°C for 15 minutes or more, but in the method 1, -1), zinc oxide It has been difficult to obtain particles with a diameter of 1 μm or less because the filler particles tend to become coarse and VV easily.This results in loss of transparency, and the conductive ultraviolet blocking film is generally about 1 to 5 μm thick, making it difficult to obtain filler particles. In the conventional method, the particle size of - is too coarse because the film surface cannot be made smooth unless it is 1/7 or less of the film thickness.

In the conventional method, an alkali is added to a coexisting solution of an acidic salt of zinc, such as zinc nitrate, and an acidic salt of aluminum, such as aluminum chloride, to produce zinc oxide and aluminum hydroxide (sometimes aluminum oxide). 600°
There is a method in which zinc oxide is doped with aluminum by heating at carbon dioxide, or a method in which aluminum oxide is mixed with zinc oxide powder and heated to dope aluminum into zinc oxide. In these Jj methods, the size of the brewed zinc before doping is 1 μm or more. In addition, even if the raw materials are carefully selected and manufactured, secondary aggregation is unavoidable, resulting in secondary particles with a particle size of 0.5 μm or more. When attempting to fully dope the center, the harsh conditions of 15 minutes or more are required at temperatures as high as 600°C or higher, and the particle size of zinc oxide is small even in terms of primary particles. μm, so one grain P is
It becomes a polycrystalline aggregate, becomes opaque due to diffuse reflection at grain boundaries, and is too coarse to be used as a paint filler.

Therefore, it is an object of the present invention to provide a coating material for a coating method that has the dual properties of conductive transparency and a transparent UV-blocking thin film, and a method for producing a transparent conductive UV-blocking thin film using the coating material.

[Means for Solving the Problems] In order to solve the above technical problems, the present invention provides zinc 1
Prepare an aqueous solution in which an acid salt of tin-zinc containing 0.02 to 5.0 moles of tin is dissolved in an amount of 75i% or less in terms of zinc oxide, and neutralize the alkaline solution. 4. A method for producing a transparent conductive ultraviolet absorbing material, characterized in that the precipitate formed in the mixed aqueous solution is washed, filtered, taken out, and heated to 400°C to 700°C. Acidic salts of tin, aluminum,
Preferred are acidic salts of indium or mixtures thereof. Further, the acid salt is preferably a chloride, a sulfur salt, a nitrate salt, or a mixture thereof. Furthermore, the present invention includes mixing the powder of the transparent conductive absorbent material with a solvent or paint, applying it on a substrate, drying it,
Remove the binder and then heat at 200°C in a reducing atmosphere.
This is a method for producing a transparent conductive thin film characterized by heat treatment at 400''C.

The inventors of the present invention discovered that by making zinc oxide particles into submicron particles and dispersing them in a brush, the diffused reflection caused by the boundaries of single crystals was eliminated, the white color disappeared, and the brush became transparent. When transparent zinc oxide powder is doped, it becomes conductive and has UV absorption of 4.
It was thought that it was close to 00n-.

That is, according to the present invention, the following conditions are required for the transparent conductive ultraviolet absorbing material.

Doped zinc oxide is the most suitable material. The thickness of the coating film is 1 to 10 μm within the film, so the filler particle size is 1/7 of 1 μm or less, that is, 0.1 μm.
It is necessary that the thickness be less than 5 μm. That is, the particle size of zinc oxide and dopant material before doping is at least 0.
．． It is necessary that it is 15 ttrn or less. However, since there is always some increase in particle size during subsequent heating, taking this into consideration, the particle size must be 0.1 μm or less. As dopants, aluminum, gallium, indium, germanium, and tin are effective for electrical conductivity. However, gallium and germanium are expensive, have problems with transparency, and furthermore, undoped a-) portions cause whitening, so they are unsuitable.

In the case of aluminum, it is easy to obtain fine grains as a doping material and the price is low, but if it is not doped, the remaining alumina will cause diffuse reflection, become white, and become transparent. This requires sophisticated manufacturing processes and techniques, such as adjusting the refractive index of the material.

In addition, when tin is used as a doping material, the conductivity of tin is slightly lower than that of using aluminum or indium, but it does not become opaque even if it remains without being doped, and it is also cost-effective. , is considerably cheaper than indium. On the other hand, in the case of indium,
It has the best conductivity and does not impede transparency even if left undoped, but it is a very expensive raw material.

For coating materials with a particle size of 0.1 μm or less, that is, by doping zinc oxide with a particle size of that size with tin and a combination of tin, indium, aluminum, etc., a previously unknown transparent material can be obtained. He thought that it would be possible to obtain a conductive ultraviolet absorber, and established the technology as described in R.

That is, methods for obtaining zinc oxide include heating and evaporating zinc metal and oxidizing it, and mixing zinc-containing minerals and carbon, heating and evaporating the mixture, and oxidizing it.$ II Adding an alkali to lead salt. There is also a method of neutralizing and precipitating, or a method of neutralizing zinc salt by adding sodium R oxide, calcining the precipitated zinc chlorate, removing the next gas, and converting it to zinc oxide, but other than the method using carbonate. The diameter of the primary particle is 1μ
m or more, and cannot be used for the purpose of paint preparation. Therefore, in the present invention, a method equivalent to the method using carbonates is used.
°

Examples of acidic salts of zinc include chloride, sulfur salt, and nitrate salt.
Either one or a mixture thereof can be used, and 0.02 to 5.0 mol of an acid salt of tin, indium, or aluminum is added as a doping agent to 100 T of the acid salt of zinc. ~Since the zinc oxide particles are small,
Doping is easy and almost no doping residue is generated, so it is preferable that 0.02 to 0.7 mol of the dopant can be used for sufficient doping.

That is, if the dopant is less than 0.02 mol, the conductivity will be insufficient, which is disadvantageous, and if it exceeds 0.7T, it will easily precipitate as an impurity, which will impede transparency and conductivity, which is disadvantageous. .

Although both zinc acid salt and tin acid salt are dissolved, water is generally used as the solvent. However, even alcohols are IIr.
It is Noh. If the concentration is high at this time, the particle size of the produced precipitate becomes large and secondary aggregation is likely to occur, so the solution must be dilute.

The concentration of zinc acid salt is 73! Must be less than if%.

Settlement sodium is added to the aqueous solution of zinc-tin acid salt prepared in this way, and a mixed precipitate of lead and the hydroxide to oxide of the dopant is produced. This is filtered, washed, dried, and heated at a temperature of 400 to 700°C for 2 minutes or more to obtain zinc oxide powder doped with a dopant material, and the particle size of the primary particles is 0. One with a diameter of 1 μm or less can be obtained.

Doping is possible even at a doping temperature of less than 40 G'C, but doping takes time and particles and
As the growth is large and the particle size exceeds 1 μm,
It's impossible. Furthermore, if doping is carried out at a temperature exceeding 700"C, the grain growth rate will increase, and even with a heating time of about 1 minute, the grain size will become 1 μm or more.
Furthermore, the local temperature difference becomes large, making it difficult to control the two particle sizes, which is not suitable.

Compared to zinc oxide, which is an electrical insulator, the doped zinc oxide powder obtained here exhibits good electrical conductivity.In addition, this powder can be mixed into paints and solvents and sufficiently dispersed to create transparent A conductive coating material can be prepared, and when a TH film is made using this coating material, it becomes completely transparent and smooth, and is a transparent conductive material that is different from the properties of zinc oxide as a conventional white pigment. A coating film can be obtained that simultaneously has two excellent properties: UV protection performance and ultraviolet blocking performance.

The alkaline content of the alkaline aqueous solution to be reacted with the m* acidic aqueous solution is preferably sodium hydroxide, potassium hydroxide, or sodium hydroxide. After the neutralization reaction, this alkalinity must be washed away from the zinc and tin deposits by washing with water.

Other alkaline substances may also be used as long as they can be easily washed away with water, such as sodium bicarbonate, calcium hydroxide, barium hydroxide, etc. You can also use

The precipitate precipitated by such a neutralization reaction is washed with water to remove M components (chlorine, sulfur PiIl [Ml, nitrate, etc.) and alkali groups (synthorium, kaliuno 1, calcilum, etc.), and then dehydrated. ,dry.

When this precipitate is dried, a fine powder is obtained.
If we measure the volume resistivity of this powder itself, we can see that it has a certain degree of conductivity.The zero volume resistivity is 1 to 3 x 10" Ωe1 m, and it is a transparent and conductive ultraviolet blocking fine granular material. Obtained.

The transparent conductive UV-blocking particulate material according to the present invention comprises:
Since it is neutralized, there is no damage caused by acid content and it can be used safely. In addition, by using such fine particle material, the UV blocking rate is 90% at a surface resistance value of around 50Ω/mouth.
A thin film with excellent transparent conductivity as described in 1. below can be obtained.

That is, this transparent conductive fine particulate material was used as H4F1fI for paint.
It can be mixed with to make a transparent conductive paint.

As the 1lllrl that can be used to prepare a paint from the transparent conductive ultraviolet blocking material according to the present invention, J61J11, which can be prepared and used by ordinary paint technology, is used, but no special restrictions are necessary, and polyvinyl acetate, ureaphor 11 Aldehyde resins, epoxy resins, polyester resins, phenolic resins, alkyd resins, polyurethane resins, vinyl resins, etc. can be used. That is, synthetic resins generally used in transparent paints can be used as the main component for forming the coating film.

As a solvent for the resin described in 1-1 above, it is also possible to use solvents such as water, alcohol, benzene, silica oil, and boiled oil. As examples of such solvents, mention may be made of methyl ethyl ketone (MEK), Schiff'n hexanone, detrafuran (THF), ethyl acetate, ahitone, lower alcohols. Also, cellosolves such as toluene, xylene, cellosolve acetate, petroleum spirits,
Solvents commonly used in paints, such as solvents and methylene chloride, may also be included.

The transparent conductive paint thus prepared was coated with ordinary H
It can be applied by a method. For those that can be used as substrates, they can be processed as follows:
For example, a glass plate, a plastic plate, etc. can be used as long as it does not lose transparency or cause significant deformation or damage.

That is, for example, a glass plate coated with the fine particle transparent conductive paint prepared as described in F below is dried and heated to evaporate the resin component.The heating temperature for this varies depending on the resin and solvent. is 80°C to 250°C, preferably 10
The temperature is 0°C to 150°C, and the binder is sufficiently evaporated.
Use a temperature range that allows you to fly. In this way, in the binder removal process, the surface resistance value is 108 to 108
It will be about Ω/mouth.

Due to the characteristics of the fine particle coating material produced by the present invention, it has excellent dispersibility and uniformity in the coating material, and therefore, a transparent conductive ultraviolet-blocking thin film with superior transmittance and surface resistance can be produced at a low cost. The technology that can provide this is what has become possible.

In the suberet method and the coating method using the 4° paint containing the fine particulate material produced in the present invention, transparent conductive fine powder is sprayed or applied, but the transparency and conductivity of the film formed in this way are , depends on the characteristics of the transparent conductive fine particles.

Therefore, in the present invention, we have established a material that makes zinc-tin-based oxide conductive and has ultraviolet a blocking performance as a transparent conductive material for spraying and coating methods, and a method for producing a thin film using the material.

That is, since it is a fine filler, it has very good dispersibility, and therefore, the coating film can be leveled and leveled very easily, and a transparent conductive coating material with superior properties can be provided. This is possible.

Further, resin components that can be used in the transparent conductive paint of the present invention include polyester resin, polyvinyl acetate,
Examples include urea formaldehyde resin, epoxy J161 resin, soenol resin, alkyd resin, and polyurethane resin.

In addition, water, alcohol, benbin, loopin, boiled oil, etc. can be used as the solvent.

The binder used in the paint of the present invention is pH-contained using known binders and known techniques. Not limited to special methods0
For example, as the binder, inorganic binders such as ethyl silicate and water glass, and organic binders such as polynisder resin and acrylic mm can be used.

The coating film produced by the coating material obtained according to the present invention is compared to the coating film produced by the coating material obtained from the method of heating and doping dry powder according to the prior art.
It is extremely superior in terms of transparency and mass production.

The transparent conductive ultraviolet-blocking material obtained by the present invention and the thin film produced therefrom can be used, for example, in window glass, electronics, etc.
It is effective when used in areas that require ultraviolet blocking, anti-static properties (i.e. dust build-up), and transparency, such as glass for copying, shades for lighting equipment, industrial vinyl house malbungs, etc. be.

Next, the method for producing a transparent conductive ultraviolet-blocking material and the method for producing a transparent conductive ultraviolet-blocking thin film according to the present invention will be specifically explained using Examples, but the present invention is not limited thereto. .

[Example 1] Zinc sulfate and tin sulfate were dissolved in pure water at a molar ratio of 100:0.6, and the zinc oxide concentration was 1 ot.
It was adjusted so that it was %. At this time, take the same amount of water as the water used as the solvent, add sodium carbonate in excess of 1 necessary for the reaction, dissolve it, add this to the zinc solution, and react. The pH at the end point is 10.
It became 2. The resulting precipitate was filtered, and when SO4 ions and Na ions were no longer detected in the filtered filtrate, water washing and filtration were stopped to obtain a precipitate cake. This precipitate cake was dehydrated and the dehydrated cake was dried at 550"C.
After baking for 10 minutes, a white powder was obtained. When the powder was measured, the particle size was 0°005-0.020 #m.
Met. The volume resistance was 15ΩC-.

38 parts by weight of the calcined powder obtained as described in Section L, parts of Bosch ξ Sprue J6111fi 7"f-121i, 25 parts of methyl ethyl ketone (MEK) and 1 part of toluene were mixed and uniformly dispersed. A transparent conductive UV-blocking paint was obtained.

Next, apply this paint to the PET film surface J2,
It was heated for 0°C12O minutes and dried to obtain a coating film with a thickness of 3 μm. When one is placed on this membrane itself and measured, the result is
Total light transmittance is 99.2%, haze value is 0.9%, ultraviolet absorption edge is 390n-, 250-400n
- It absorbed ultraviolet rays with an absorption rate of 99.2%. When measured on this film itself, the surface electrical resistance is 6x10"
It was Ω/mouth.

[Example 2] The molar ratio of 11r lead and indium 11 in water was 100:0°6
Zinc nitrate and indium nitrate were dissolved and the concentration in terms of opened zinc was adjusted to 10% by weight to obtain an aqueous solution. The solvent water used at this time and the company's water were taken, and sodium carbonate in excess of the amount required for neutralization was added to obtain an alkalizing aqueous solution. This aqueous solution was added to the zinc aqueous solution and neutralized to pH 10.5,
A precipitate was obtained. This precipitate was filtered, dehydrated, and then washed with water. The filter cake was washed with water and taken out when nitrate ions were no longer detected, and was dried at 100°C. After drying, it was baked at 550°C for 10 minutes to obtain a particle size of o, oos to 0.
The zero volume resistance obtained from the powder of particles of 020 μm is 3Ω (j
Met.

Next, parts by weight of this powder 3B, 12 parts by weight of polyester resin monomer, 25 parts by weight of MEK, and 25 parts by weight of toluene! it
The components were mixed and dispersed uniformly to form a paint. PET this
Coat it on a film, heat it at 120℃ for 20 minutes, and reduce the thickness to 3μm.
A thick coating film was obtained. The total light transmittance of the film itself is 98.7%
The haze value is 1.3%, and the ultraviolet absorption edge is
3940 so, the ultraviolet absorption rate in the wavelength range of 250 to 400 nm is 99.7%, and the surface electrical resistance is 2×
It was 10 IΩ/mouth.

[Example 3] 111: Molar ratio of lead and aluminum is 100:0゜0
6, and zinc nitrate and ammonium light were dissolved in water so that the zinc oxide concentration was 10% by weight to obtain a zinc aqueous solution. Take the same amount of water as the solvent water used at this time, dissolve an amount of sodium carbonate in excess of the amount required for neutralization, add this to the zinc aqueous solution, and continue neutralizing. , the pH became 9.8. The obtained precipitate was washed and filtered, and when nitrate ions and sulfate ions in the filtrate were no longer detected, it was taken out, dried, and calcined at 600° C. for 5 minutes. The thus obtained fired powder had a volume resistivity of 2×10”ΩC−.

Parts by weight of this powder 3B, 12 parts by weight of polyester resin monomer, 25 parts by weight of MgX, and 25 parts by weight of toluene were mixed and uniformly dispersed to obtain a transparent conductive ultraviolet blocking coating.

This coating material was applied to a PET film and heated at 120° C. for 20 minutes to obtain a coating film with a thickness of 3 μm.

When this film itself was measured, the results showed that the total light transmittance was 98.3%, the haze value was 2.2%, the ultraviolet absorption edge was 387n■, and the ultraviolet ray region from 250 to 400n- When measuring the 0, - film itself, which had an absorption rate of 98.9% C, the surface electrical resistance was 10'Ω/mouth.

[Effects of the Invention] The following remarkable technical effects were obtained by the method for producing a transparent conductive ultraviolet blocking paint and the method for producing a transparent conductive film using the same according to the present invention.

First, it is possible to fabricate a material that has two properties, transparent conductivity and conductive ultraviolet absorption, and a thin film made from the same.

Second, it meets the strict requirements for transparent conductive UV blocking performance.
A transparent conductive thin film can be produced.

Thirdly, we were able to provide a transparent conductive ultraviolet absorbing material that can reduce manufacturing costs and an economical method for manufacturing such a thin film.

Patent Applicant Sumitomo Himento Co., Ltd. Agent Hiroshi Kuramochi Procedural Amendment Written by Patent Office Officer, February 3, 1999, 1986 Patent Application No. 321971 2, Title of the invention: Transparent conductive ultraviolet absorbing material and its manufacturing method 3, Relationship with the amended party case Applicant address: 1, Kanda Mitoyo-cho, Chiyoda-ku, Tokyo Name: Representative of Sumitomo Cement Co., Ltd. Hikoji Imayo 4, Agent address: 1-2 Kanda Suda-cho, Chiyoda-ku, Tokyo 101 [
1 Ho-Shikoku Building 3F 5. Subject of amendment] 6. Contents of amendment (1) [Claims (1)] of the specification will be corrected as shown in the attached sheet.

(2) Page 7, line 12 of the specification [1 [doped Mi+]
Correct 1 to [after doping].

(3) Same as page 7, line 17, [harsh] [/・Y harsh]
BT corrects.

(4) Correct "alkaline solution" to "alkaline solution" on page 8, line 12 of the same page.

(5) Correct ``kuma aru'' in ``kuma aru'' to ``kuma na ni'' in line 12, line 12 of the 9th sentence of the same letter.

(6) Correct "as a material" in the 16th line of No. 9, ditto, to "as an ultraviolet absorbing material."

(7) Change the combination of [etc.] in page 11, line 8 of the same 1 to [
etc. to severe condition or combination].

(8) Same, E, page 13, line 13, ``Particle growth becomes large'' is corrected to ``On the contrary, particles/growth become larger.''

(9) On page 13, line 14 of the same page, correct [because it will become like this] to [because it will become like that].

(lO) Same [-1400, line 13, [must be washed away] is corrected to [must be removed].

(tt) Same 170th line 5 [1(7) [Tr! Corrected to [M, zinc oxide-containing I paint].

(12) Same) - Page 17, line 16 [The barrier thin film]
Correct it to [blocking thin film].

(13) In the same page, 17rt, lines 19-20, [In the spray method and coating method, transparent conductive fine powder is sprayed or coated] is revised to [In the coating method,] .

(14) Correct [fine particles] in the second line of page 18 to [fine particles -1i4 bodies].

(15) Same 1; [Zinc-tin system] in the 4th line of the 18th true [
Zinc - tin, aluminum; - ram, indium system].

(16) Identical; 1800th line, 5th line, [conductivity] is changed to [conductivity] [1:ζ゛].

(17) In the same paragraph, No. 1, 1800, line 5, ``Materials available'' was corrected to ``Pigments used.''

(18) [Thin film production Jj method], page 1-18, line 6
is corrected to [Coating film preparation Jj method].

Claims (1) A doping agent containing 0.02 to 5.0 moles of tin per ioo mole of zinc - an aqueous solution prepared by dissolving not more than 7% by weight of an acid salt of zinc in terms of zinc oxide. , a process for producing a transparent conductive ultraviolet absorbing material characterized by neutralizing this with an alkaline solution, washing the precipitate formed in the mixed aqueous solution, filtering it, taking it out, and heating it to 400°C to 700°C. .

Claims (4)

[Claims] (1) A doping agent containing 0.02 to 5.0 moles of tin per 100 moles of zinc - Prepare an aqueous solution in which an acid salt of zinc is dissolved at 7% by weight or less in terms of zinc oxide, and add it to an alkali solution. 1. A method for producing a transparent conductive ultraviolet absorbing material, which comprises neutralizing a solution, washing, filtering, and taking out a precipitate formed in the mixed aqueous solution and heating it to 400°C to 700°C. (2) The method according to claim 1, wherein the dopant comprises an acid salt of tin, aluminum, or indium, or a mixture thereof. (3) The method according to claim 1, wherein the acid salt is a chloride, a sulfate, a nitrate, or a mixture thereof. (4) The powder of the transparent conductive absorbent material according to claim 1 is mixed with a solvent or paint, applied onto a substrate, dried to remove the binder, and then heated at 200°C to 400°C in a reducing atmosphere. ℃
1. A method for producing a transparent conductive thin film, which is characterized by heat treatment.