JPH01144520A - Manufacture of electricity conductive film - Google Patents

Abstract

PURPOSE:To manufacture a superconductive film excellent in both transparency and close contact property, and showing high superconductivity by applying and solidifying a moisture-hardening type urethane resin on a supporting body to form a base application layer on which solution of a semiconductor compound is applied. CONSTITUTION:A base application layer is formed for example on a film of polyethylene telephthalate by applying, drying and solidifying a solution made by dissolving a moisture hardening type urethane resin made of an adduct of trimethylole propane of trirene di-isocyanate into dichloromethane by application through an extrusion hopper. On the base application layer, a semiconductor compound solution containing copper iodide in acetonitrile is applied and dried. The solution is absorbed in the base application layer to form a superconductive layer consisting of fine particles of CuI on the base application layer. Through this method, a superconductive film excellent in both transparency and close contact property and having a high superconductivity can be manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for producing a transparent conductive film having an electrically conductive coating.

(Prior art) Transparent conductive films are used as base materials for electrophotographic recording, base materials for electrostatic photographic recording, transparent electrodes for 8-inch liquid crystal displays, transparent electrodes for dispersion type EL, transparent electrodes for touch panels,
It has a wide range of applications, including clean rooms, meter windows, antistatic films for VTR tapes, and transparent heaters.

Among conventional transparent conductive films, tin-topped indium oxide film (Indium T
in Oxide-ITO film), antimony-doped tin oxide film, cadmium tin oxide film ((:adm
ium Tin Oxide-C70 film), copper iodide film, titanium oxide film, and zirconium oxide film.

Among these, ITO film is the most excellent in both transparency and conductivity. Tin oxide film requires a high substrate temperature for film formation, making it difficult to apply to polymer films.C70 film has a smaller energy gap than indium oxide film (absorption edge is on the long wavelength side) and film thickness. As it grows, it becomes slightly yellowish. Copper iodide films, titanium oxide films, and zirconium oxide films are inferior in both transparency and conductivity compared to these films.

In addition, these semiconductor thin conductive films are created through vapor deposition and subsequent processing steps, but large-scale manufacturing equipment is required.
Therefore, it was expensive.

One way to form such a semiconductor thin film at low cost is to create a transparent conductive film by applying an undercoat to a polymer film in advance and absorbing a semiconductor compound onto the surface of the layer, which is effective in adhering to the support and upper layer. (Japanese Patent Publication No. 48-9984).

(Problems to be Solved by the Invention) Conventional undercoating is performed using a hydrophobic, electrically insulating polymer material that has adhesive properties to the support, but such transparent conductive films do not adhere well. Although the properties and transparency were excellent, the conductivity was not sufficient.

(Means for solving the problem) The present inventors have conducted intensive research to overcome the drawbacks of conventional transparent conductive films, and as a result, we have developed a film that coats a moisture-curable urethane resin as an undercoat layer. , by curing, the swelling property of the semiconductor compound solution applied thereon by the solvent is controlled within a predetermined range, and a conductive layer is formed in which the semiconductor compound is present in the highest concentration near the opposite surface of the support. Based on this knowledge, the present invention has been completed.

That is, in the present invention, a moisture-curable urethane resin is applied onto a support and cured to form an undercoat layer, and a conductive layer is formed by applying a solution containing a semiconductor compound onto the undercoat layer. The present invention provides a method for manufacturing a conductive film characterized by the following.

In the present invention, conventionally known supports can be used. For example, polyesters such as polyethylene terephthalate, polyolefins such as polyethylene and polypropylene, celluloses such as cellulose acetate, polymethyl methacrylates, nylon 6, etc. Also usable are polyamides, polyimides, polycarbonates, polyvinyl alcohols, vinyl chloride-vinyl acetate copolymers, glass, and coated paper coated with the above-mentioned polyolefins and polyesters.

In the present invention, a moisture-curable urethane resin undercoat layer is formed on such a support.

The moisture-curing urethane resin used in the present invention is a one-component curable urethane resin that absorbs moisture in the air and undergoes a three-dimensional crosslinking reaction to cure. Such moisture-curable urethane resins are resins in which polyhydric alcohols are reacted with excess diisocyanate to leave free isocyanate groups at the ends, and are generally resins that harden when the isocyanate groups react with moisture. Further, when a non-yellowing diisocyanate is used, a catalyst such as dibutyltin dilaurate may be used as a reaction accelerator.

The polyhydric alcohols used here include ethylene glycol, propylene glycol, 1,3-butylene gelicol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, neopentyl glycol, triethylene glycol, and hydrogenated bisphenol A.
, bisphenol dihydroxypropyl ether, glycerin, trimethylolethane, trimethylolpropane, trishydroxymethylaminomethane, pentaerythritol, dipentaerythritol, and the diisocyanates include 2.4-tolylene diisocyanate, 2.6- Tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, paraxylylene diisocyanate, metaxylylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), methylcyclohexane-2,4-diisocyanate, methyl Examples include cyclohexane-2,6-diisocyanate, 1,3-(isocyanatomethyl)cyclohexane, isophorone diisocyanate, trimethylhexamethylene diisocyanate, dimer acid diisocyanate, and the like. Other moisture-curable urethane resins include triphenylmethane triisocyanate, naphthylene-1,5-diisocyanate, and polymethylene polyphenylisocyanate. In addition, blocked isocyanates blocked with phenols, phenols such as cresol, and alcohols can be used, but are not particularly limited to these.

In addition to the moisture-curing urethane resin, the undercoat layer of the present invention contains
It may also contain other resins that are compatible with these compounds. For example, styrene-butadiene copolymers, styrene resins, alkyd resins.

Vinyl chloride resin, vinyl chloride-vinyl acetate resin, polyvinylidene chloride resin, vinyl acetate resin, polyvinyl acetal, polyacrylic acid ester, polymethacrylic acid ester, isobutylene polymer, polyester, ketone resin, polyamides, polycarbonates, polythiocarbonate Examples thereof include copolymers of vinyl haloarylates, vinyl acetates, etc., but are not particularly limited thereto.

The thickness of the undercoat layer is not particularly limited, but may be 0. O1~100 end,
Preferably it is 0.05 to 10 IL.

In the present invention, the undercoat layer swells and absorbs the semiconductor compound solution during coating treatment with a solvent for the semiconductor compound solution, but does not dissolve (has solvent swellability). This is considered to be due to the three-dimensional network structure. This also results in the formation of a conductive layer near the surface of the undercoat layer.

The moisture-curable urethane resin used in the present invention is
Swelling degree ΔT/T, -To (To is the film thickness before immersion, T1
is the film thickness after immersion for 5 minutes in a solvent that dissolves semiconductor compounds,
ΔT is the measured displacement in film thickness). When is about 1 OIL, it is preferably in the range of 1.05 to 2.5, more preferably 1.05 to 1.7.

A preferred method for making the conductive layer of the present invention is to apply a solution of a semiconductor compound solubilized in a volatile solvent to a base coat layer of a cured moisture-curing polyurethane resin on a suitable support. In this method, the coating liquid is absorbed into the undercoat layer, and the solvent is evaporated.

Semiconductor compounds used in the conductive layer of the conductive thin film of the present invention are preferably cuprous iodide and silver iodide, but other metal-containing semiconductor compounds, such as other cuprous halides; Silver: bismuth, gold, indium, iridium, lead, nickel, palladium, rhenium, tin, tellurium, and tungsten halides: cupric, cupric, and silver thiocyanate; or iodomerculate, etc. may also be used.

Metal-containing semiconductor compounds are not readily soluble in most volatile solvents such as water and many organic solvents. Compounds which form soluble complex salts with semiconductors can therefore be used as solubilizers for semiconductors.

In general, alkali metal pallites and ammonium halides can be used as complexing agents with certain semiconducting metal halides such as silver halides, cupric halides, tin halides, lead halides, and others; Although it is usually preferred to remove the solubilizing agent, for example by washing with water, in some embodiments the complex salt itself provides sufficient conductivity. In the latter case, the complex compound itself is a semiconductor compound. Examples of volatile ketone solvents suitable for dissolving these complex compounds are acetone, methyl ethyl ketone, 2-pentanone, 3-pentanone, 2-hexane, 2-heptanone, 4-heptanone, methyl isopropyl ketone, ethyl isopropyl ketone, Diisopropyl ketone, methyl isobutyl ketone, methyl-t-
butylketone, diacetyl, acetylacetone.

These include acetonyl acetone diacetone alcohol, mesityl oxide, chloroacetone, cyclopentanone, cyclohexanone, and acetophenone. Mixtures of ketone solvents can also be used, and in some cases a single ketone solvent can be used. In some cases, some solvents other than ketones may be used to dissolve the iodide complex compound, particularly when lithium iodide, sodium iodide are used as complexing agents. Methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, iso-amyl acetate, tetrahydrofuran, dimethylformamide solve, methyl cellosolve acetate, ethyl acetate and others to dissolve iodide complex compounds It can be used effectively.

As a solvent for cuprous iodide, acetonitrile can be used because cuprous iodide and acetonitrile form a complex salt.

Preferably, the semiconductor compound is used as a solution with a concentration of 0.1 to 50% by weight. Also, add 40 to 2000 mg of this solution.
It is preferable to apply at a ratio of /rn', especially 100
It is preferable to apply at a rate of -1000 mg/rn''.

The transparent conductive film of the present invention can be obtained by forming a moisture-curable urethane undercoat layer on a support, and applying a solution of a semiconductor compound thereon to form a conductive layer. The curing time is not particularly limited and varies depending on the curing temperature.

Methods for applying a solution of a semiconductor compound include, for example, spin coating, dip coating, spray coating, beat coating using a continuous coating machine,
There are methods such as a continuously moving wick method, a coating method using a hopper, etc., but the method is not particularly limited thereto.

The method of forming such a conductive layer itself is described in Japanese Patent Publication No. 48-998.
4, No. 46-34499.

(Effects of the Invention) The conductive film obtained by the method of the present invention has excellent transparency and adhesion of the conductive layer, and particularly exhibits high conductivity. This transparent conductive film is used as a base material for electrophotographic recording, a base material for electrostatic photographic recording, transparent electrodes for thin liquid crystal displays, transparent electrodes for distributed EL, transparent electrodes for touch panels, clean rooms, meter windows, VTR tapes, etc. It can be used in a wide range of applications such as preventive films and transparent heaters.

(Example) The present invention will be explained in more detail below based on examples.

Example 1 A solution prepared by dissolving 5.0 g of a moisture-curable urethane resin consisting of a trimethylolpropane adduct of tolylene diisocyanate in 95.0 g of dichloromethane was applied onto a 100 IL thick polyethylene terephthalate film using an extrusion hopper. Dry at °C. The thickness of this undercoat layer is approximately 0.5. There was. This film was heated at 50℃80%RH.
It was left to stand for one day to harden. Then add 97g on top of this layer.
A solution containing 3 g of cupric iodide in acetonitrile was applied at a dry weight of 0.3 g/m' and heated at 100°C.
and dried. Although this solution does not contain a binder, it is absorbed by the undercoat layer, forming a fine particle layer of CuI mainly on top of the undercoat layer. , the surface resistance of this conductive film was determined by Loresta M
Results measured with CP-TESTER (manufactured by Mitsubishi Yuka Co., Ltd.) 1. It was OX10'Ω/mouth.

Example 2 Moisture-curable urethane resin: Coronate L (trade name,
(manufactured by Nippon Polyurethane Co., Ltd.) 4.0g, polyester resin;
A solution prepared by dissolving 3.0 g of Polyester Adhesive 49000 (trade name, manufactured by DuPont) in 93.0 g of dichloromethane was applied using an extrusion hopper and dried at 100°C. The film thickness of this undercoat layer was approximately 0.3 mm. This film was left to stand at 50'C, 80% RH for 2 days to cure. On top of this layer, a solution containing 3 g of cupric iodide in 97 g of acetonitrile was applied at a dry weight of 0.3 g/m'' and dried at loo'c.The surface resistance of this conductive film was 1 .O
Xlo4Ω/mouth.

Example 3 Polyester adhesive 490000 of Example 2, 3 g
Example 2 was carried out in exactly the same manner, except that the polymers listed in Table 1 were used instead of the polymers listed in Table 1. All of the obtained conductive films showed good conductivity.

Example 4 Coronate L4 of Example 2. Example 2 was carried out in exactly the same manner except that a moisture-curable urethane resin (polyisocyanate) listed in Table 2 was used instead of Og. All showed good conductivity.

Comparative Example 1 A solution of polyester adhesive 490005, Og dissolved in 95.0 g of methyl ethyl ketone was applied onto a 100 IL thick polyethylene terephthalate film using an extrusion hopper and dried at 100°C. The thickness of this undercoat layer was about 0.5 IL. A solution of 3 g of cupric iodide in 97 g of acetonitrile was applied onto this layer at a dry weight of 0.3 g/rn' and dried at 100'C. The surface resistance of this conductive film is 5.0xlO9Ω
/It was a mouth.

Comparative Example 2 Instead of the undercoat layer of Comparative Example 1, 5.0 g of a resin prepared by copolymerizing vinylidene chloride, acrylonitrile, and acrylic acid at a ratio of 80:19:1 (weight ratio) was mixed with 95 g of dichloromethane.
．． Apply the solution dissolved in 0g using a hopper and apply 1
It was dried at 00°C.

The thickness of this layer was approximately 0.51L. Then Example 1
A conductive film was prepared in exactly the same manner as above, and the surface resistance was measured to be 3.0xlO6Ω/mouth.

Example 5 Thickness: 100. An undercoat layer of approximately 0.3 mm was provided on the polyethylene terephthalate film by the same procedure as in Example 2. After this film was left to stand at 50°C and 80% RH for 2 days to cure, a solution of 776 g of silver iodide and 2.14 g of potassium iodide dissolved in 2-butane was added to the film at a dry weight of 0.6 g/rrf. It was applied at a ratio of 100°C and dried at 100°C. The resistance of this conductive film was 3°0×10 6 Ω/hole.

As shown in Examples 1 to 4, conductive films using a moisture-curable polyurethane resin for the undercoat layer exhibit better conductivity than the comparative examples.

Establishment of procedure (voluntary) April 19, 1988 Director General of the Patent Office Kunio Ogawa 1. Indication of s Patent Application No. 304090 1988 2. Title of invention Method for manufacturing conductive film 3. Amendment Relationship with the case of a person who does
0) Fuji Photo Film Co., Ltd. Representative: Minoru Ohnishi 4, Agent address: 7th floor, Midoriya Building 2, 3-7-3 Shinbashi, Minato-ku, Tokyo 105 Telephone: (03) 591-7387.

6. Column 7 of "Detailed Description of the Invention" of the specification subject to amendment. Contents of amendment (1) Delete "Transparent" in line 7 from the bottom of the first page of the specification.

(2) Add "Is this a semiconductor compound" next to "This solution" on page 11, line 9 of the same book.

(3) On the 13th line of the same page of the circular, after “on the support”, “
Add "Hardened".

(Above) Procedural auxiliary device (spontaneous) September 8, 1988 Director General of the Japan Patent Office Yoshi 1) Takeshi Moon 1, Indication of Is Patent Application No. 304090 of 1988 2, Title of invention Method for manufacturing conductive film 3 , Relationship with the case of the person making the amendment Patent applicant address 210 Nakanuma, Minamiashigara City, Kanagawa Prefecture Name (52
0) Fuji Photo Film Co., Ltd. Representative Minoru Ohnishi 4, Agent address 7th floor, Midoriya Building 2, 3-7-3 Shinbashi, Minato-ku, Tokyo 105 Telephone (03) 591-7387 Name (7643) Patent attorney Mei 1) Toshi 35, date of amendment order Voluntary action 6, subject of amendment 7, content of amendment (1) "ΔT/T1-To" on page 8, line 6 of the specification
Correct to "T1/To".

(2) Delete "QΔT is the displacement of..." from lines 8 to 9 on the same page of the same book.

(3) r3.0Xlo J on the bottom line of page 18 of the same book
Correct to r3.0xlO7J.

(that's all)

Claims (1)

[Claims] 1. A conductive layer is formed by coating a moisture-curing urethane resin on a support and curing it to form an undercoat layer, and then applying a solution containing a semiconductor compound onto this undercoat layer. A method for producing a conductive film characterized by: