JP2001093336A - Transparent conductive film and its grounding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transparent conductive film superior in antistatic, electromagnetic shielding and bonding performances in use for a front plate or an antistatic mat on a cathode ray tube or a plasma display and capable of grounding. SOLUTION: A transparent conductive film having at least one conductive layer on one side of a substrate comprises at least one undercoat layer on the substrate at the side of the conductive layer, the conductive layer containing silver colloidal particles having particle sizes of 1-200 nm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent conductive film having an excellent antistatic effect, an electromagnetic wave shielding effect and a mechanical strength characteristic, and more particularly to a film having excellent adhesion to a substrate (hereinafter also referred to as a substrate). The present invention relates to a transparent conductive film having no surface and excellent planarity.

[0002]

2. Description of the Related Art In recent years, in the field of electronic equipment, transparent antistatic and electromagnetic wave shielding materials have become necessary for various devices. Is desired. In particular, the cathode ray tubes and plasma displays used in these devices can reduce the visibility due to static electricity generated on the image surface and reduce visibility, and as a more serious problem, radiate electromagnetic waves and adversely affect the surroundings. And
In recent years, it has been studied and developed as a so-called electromagnetic interference problem. Further, flattening of the cathode ray tube or the like has caused a problem that an antireflection function is required, fingerprints are made by touching an image surface, and scratches are easily generated when removing dirt. In order to prevent dust and electromagnetic interference caused by these problems, a method of forming a conductive layer by depositing / sputtering a conductive metal such as silver or a conductive metal oxide such as ITO, or a mesh of a thin metal wire. Improvements have been proposed by forming a layer or the like. At this time, the conductive film needs to be transparent, and when a conductive layer is formed using a large amount of a conductive material, there is a problem that the transparency is lost, and it has been difficult to design the conductive layer. In order to protect these conductive layers from dirt and scratches generated during production and handling, a protective layer and an antifouling overcoat layer are usually provided thereon. Furthermore, it is also common to provide a film such as a refractive index control layer for providing an antireflection function. For example, it is known that an inorganic oxide film such as silica having a different refractive index from the conductive layer is formed by alternately overlapping the conductive layer to control the reflectance.

Further, the above-mentioned electromagnetic wave shielding, which has recently attracted attention, needs to be grounded. However, when a protective layer for these conductive layers is formed, the conductivity may be obtained from the surface of the protective layer. It became difficult, and it was necessary to expose and electrically ground the conductive layer by some means. Therefore, it is necessary to ground the conductive layer by peeling off the protective film on the surface or penetrating the protective film. Therefore, in these processing steps, the conductive layer is often scratched and deteriorated in weather resistance, and the protective film and other functional layers are often damaged, thereby impairing the commercial value. Further, it has a drawback that it imposes a heavy load on cost and is inferior in productivity. These improvements are:
It has been found that it can be improved by properly designing the protective layer above the conductive layer. However, the substrate is required to be transparent, and generally a hydrophobic plastic is used. In such a case, it is known that, when a constituent layer such as a conductive film is applied, poor adhesion between the base and the constituent layers becomes a problem, and improvement thereof has been desired. Furthermore, it has been found that these primers play an important role on surface texture and scratches.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a transparent conductive film having excellent antistatic properties, electromagnetic wave shielding properties and mechanical strength properties.
In particular, the present invention relates to a transparent conductive film which is excellent in adhesion to a substrate, has no film peeling, and has excellent surface properties.

[0005]

The object of the present invention has been solved by the following invention. 1) A transparent conductive film having at least one conductive layer on one side of a base material, the base material having at least one undercoat layer on the conductive layer side of the base material, and the conductive layer having a particle size of 1 to 2
A transparent conductive film, which is a layer containing 00 nm colloidal silver particles. 2) The transparent conductive film as described in 1) above, wherein the undercoat layer of the substrate is a layer containing at least one of a hydrophobic polymer and a hydrophilic polymer. 3) The transparent conductive film as described in 1 or 2 above, wherein the undercoat layer of the base material contains at least one surfactant. 4) The transparent conductive film as described in 1) to 3) above, wherein the undercoat layer of the base material contains at least one hardener. 5) The transparent conductive film as described in 1) to 4) above, wherein the substrate is surface-treated before the undercoat layer is applied. 6) The surface treatment of the base material includes an ultraviolet treatment, a glow discharge treatment,
The transparent conductive film according to any one of 1) to 5) above, which is a corona discharge treatment or a flame treatment. 7) The transparent conductive film as described in 1) to 6) above, wherein the resistance of the conductive layer is 10 KΩ or less at an applied voltage of 90 V. 8) The transparent conductive film as described in 1) to 7) above, wherein the silver colloid contains 1 to 30% by weight of palladium. 9) The transparent conductive film as described in 1) to 8) above, wherein at least one protective layer is provided outside the conductive layer. 10) The transparent conductive film as described in 1) to 9) above, wherein the substrate is a plastic film having a hard coat layer. 11) A grounding method characterized in that the conductive film is grounded by directly attaching a conductive tape or the like to the surface of the conductive film according to 1) to 10).

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. First, when describing the substrate of the present invention, glass or plastic film is preferably used. Examples of the plastic film include polyester such as polyethylene terephthalate, polyethylene naphthalate, a copolymer or mixture of polyethylene terephthalate and polyethylene naphthalate, polycarbonate, norbornene-based resin (cyclic olefin copolymer), and cellulose such as triacetyl cellulose and diacetyl cellulose. Films such as resin, polyarylate, and polymethacrylic acid methyl ester are preferred. For these films,
Although the thickness is not particularly limited, it is usually 20 to 10000 μm.
m is preferable, 20 to 5000 μm is more preferable, and 3
0 to 3000 μm is particularly preferred.

Next, the present invention is characterized in that at least one undercoat layer is provided on the conductive layer side. The configuration of the undercoat layer used in the present invention has been variously devised, and it may be only necessary to provide a layer that adheres well to the substrate as a single layer,
There is a so-called multilayer method in which two or more constituent layers are further provided thereon and a resin layer that adheres well is applied. In the single layer method or the multilayer method, a resin layer containing both a hydrophobic group and a hydrophilic group may be applied. The material that can be used for the undercoat layer of the present invention is not particularly limited, and the hydrophobic polymer is selected from, for example, vinyl chloride, vinylidene chloride, butadiene, methacrylic acid, acrylic acid, itaconic acid, and maleic anhydride. Starting with copolymers starting from monomers, polyethyleneimine, epoxy resin, nitrocellulose, polyvinylbromide, polyvinylfluoride, polyvinylacetate, chlorinated polyethylene, chlorinated polypropylene, brominated polyethylene, chloride Rubber, vinyl chloride-ethylene copolymer, vinyl chloride-propylene copolymer, vinyl chloride-styrene copolymer, isobutylene chloride copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-styrene-maleic anhydride Copolymer, vinyl chloride-styrene-acrylonitrile copolymer Vinyl chloride -
Butadiene copolymer, vinyl chloride-isoprene copolymer, vinyl chloride-chlorinated propylene copolymer, vinyl chloride-vinylidene chloride-vinyl acetate terpolymer, vinyl chloride-acrylate copolymer, vinyl chloride- Maleic acid ester copolymer, vinyl chloride methacrylic acid ester copolymer, vinyl chloride-acrylonitrile copolymer, internally plasticized polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinylidene chloride, vinylidene chloride-methacrylic acid ester Halogen-containing synthetic resins such as copolymers, vinylidene chloride-acrylonitrile copolymers, vinylidene chloride-acrylate copolymers, chloroethyl vinyl ether-acrylate copolymers, and polychloroprene.

Further, polyethylene, polypropylene,
Polybutene, poly-3-methylbutene, poly-1,2-
Α-olefin copolymer such as butadiene, ethylene-propylene copolymer, ethylene-vinyl ether copolymer, ethylene-propylene-1,4-hexadiene copolymer, ethylene-vinyl acetate copolymer, butene-1-
Propylene copolymer, butadiene-acrylonitrile copolymer and blends of these copolymers with halogen-containing resins, acrylate methyl ester-acrylonitrile copolymer, acrylate ethyl ester-styrene copolymer, methacrylate methyl ester -Acrylonitrile copolymer, polymethyl methacrylate, methyl methacrylate-styrene copolymer, methacrylic acid butyl ester-styrene copolymer, polymethyl acrylate, poly-α-methyl methyl acrylate, polymethoxy acrylate Ethyl ester, polyglycidyl acrylate, butyl acrylate, methyl acrylate, ethyl acrylate, acrylate-butyl acrylate copolymer, acrylate-butadi Acrylic resin such as styrene-styrene copolymer, methacrylate-butadiene-styrene copolymer, polystyrene, poly-α-methylstyrene, styrene-dimethyl dimethyl fumarate, styrene-maleic anhydride copolymer Styrene-butadiene copolymer, styrene-butadiene-acrylonitrile copolymer, poly-2,6-dimethylphenylene oxide, styrene-acrylonitrile copolymer, polyvinylcarbazole, poly-p-xylylene, polyvinylformal, polyvinylacetal, polyvinyl Butyral, polyvinyl phthalate, cellulose triacetate, cellulose butyrate, cellulose butyrate, cellulose phthalate, nylon 6, nylon 66, nylon 12, methoxymethyl-
6-nylon, nylon 6, 10 polycapramide, poly-N-butyl-nylon-6 polyethylene sebacate,
Polybutylene glutarate, polyhexamethylene adipate, polybutylene isophthalate, polyethylene terephthalate, polyethylene adipate, polyethylene adipate terephthalate, polyethylene-2,6-naphthalate, polydiethylene glycol terephthalate,
Polyethylene oxybenzoate, bisphenol A-
Oligomers or polymers such as isophthalate, polyacrylonitrile, bisphenol A-adipate, polyhexamethylene-m-benzenedisulfonamide, polytetramethylene hexamethylene carbonate, polydimethylsiloxane, polyethylene methylene bis-4-phenylene carbonate, bisphenol A-polycarbonate (For these, see EHImmergut “Po
lymer Handbook "IV187-231, Intersciense P
ub. New York 1966).

Examples of the hydrophilic polymer used in the undercoat layer of the present invention include water-soluble polymers, cellulose esters, latex polymers, and water-soluble polyesters. Examples of the water-soluble polymer include gelatin, a gelatin derivative, casein, agar, sodium alginate, starch, polyvinyl alcohol, a polyacrylic acid copolymer, and a maleic anhydride copolymer. And so on. Latex polymers include vinyl chloride-containing copolymers, vinylidene chloride-containing copolymers,
Acrylic ester-containing copolymers, vinyl acetate-containing copolymers, butadiene-containing copolymers, and the like. As gelatin, so-called lime-processed gelatin, acid-processed gelatin,
Any of gelatin derivatives generally used in the art, such as enzyme-treated gelatin, grafted gelatin, etc., and modified gelatin can be used. In the case of a synthetic hydrophilic compound, other components may be copolymerized. is there. These hydrophilic colloids may be used alone or as a mixture of two or more.

The above-listed polymers are used alone or in a mixture of several kinds, and can be cured by adding a known crosslinking agent of epoxy type, aziridine type, isocyanate type, and / or a radiation-curable vinyl type monomer. .
As the isocyanate-based crosslinking agent, two isocyanate groups are used.
Polyisocyanate compounds having at least one polyisocyanate, for example, tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, hexamethylene diisocyanate,
Isocyanates such as xylylene diisocyanate, naphthylene-1,5-diisocyanate, o-toluidine diisocyanate, isophorone diisocyanate, triphenylmethane diisocyanate, and the reaction products of these isocyanates with polyalcohols (for example,
A reaction product of 3 mol of toluene isocyanate and 1 mol of trimethylollopane), and a polyisocyanate formed by condensation of these isocyanates. Crosslinking agents other than isocyanates include aldehydes (formaldehyde, glutaraldehyde, etc.), epichlorohydrin resins, and polyamide-epichlorohydrin resins (JP-A-51-3619).
No.), cyanuric chloride type compounds (for example,
Compounds described in JP-A-6151 and JP-A-56-130740), vinylsulfone or sulfonyl compounds. These crosslinking agents are 0.1 to 50% by weight, preferably 1 to 20% by weight, based on the whole binder including the crosslinking agent.

The undercoat layer of the present invention may contain fine particles as a matting agent. Silica (SiO ₂ ), titanium dioxide (Ti)
O ₂ ), calcium carbonate, magnesium carbonate and the like can be used. As the organic fine particle matting agent, polymethyl methacrylate, cellulose acetate propionate, polystyrene and the like can be used. The average particle diameter of these fine particle matting agents is preferably 0.01 to 5 μm. More preferably, it is 0.05 to 3 μm. Further, the content is preferably 0.05 to 50 mg / m ^{2, and} more preferably 0.5 to 20 mg / m ² .

[0012] In addition, various additives can be contained in the undercoating liquid as required. For example, a surfactant described below, an antistatic agent, an antihalation agent, a coloring dye,
Pigments, coating aids, antifoggants and the like. Furthermore, a solvent that swells the substrate may be included to improve the adhesion to the substrate.

The undercoating liquid according to the present invention can be applied by a well-known coating method such as a dip coating method, an air knife coating method, a curtain coating method, a roller coating method, and a wire coating method. The coating can be performed by a bar coating method, a gravure coating method, a slide coating method, or an extrusion coating method using a hopper described in U.S. Pat. No. 2,681,294. . If desired, U.S. Pat. Nos. 2,761,791, 3,508,947, 2,941,898 and 3,526,528, Yuji Harazaki, "Coating Engineering" 253 Two or more layers can be applied simultaneously by the method described on the page (1973, published by Asakura Shoten).

Next, the substrate of the present invention is preferably subjected to a surface treatment before applying an undercoat layer. Since the base material of the present invention has a hydrophobic surface, various treatments on the surface enable strong adhesion with an undercoat layer provided thereon. The surface treatment used in the present invention is not particularly limited as long as the adhesion between the substrate and the undercoat layer can be improved, but preferably, ultraviolet treatment, corona discharge treatment, glow discharge treatment, flame treatment, high frequency treatment, active plasma treatment,
Surface activation treatment such as laser treatment, mechanical treatment, mixed acid treatment, and ozone oxidation treatment.

Preferred among the surface treatments are ultraviolet irradiation treatment, corona treatment, glow treatment, and flame treatment. First, the ultraviolet irradiation treatment will be described below. These are JP-B-43-2603, JP-B-43-2604, and JP-B-4
It is preferably performed by the processing method described in JP-A-5-3828. The mercury lamp is a high-pressure mercury lamp composed of a quartz tube, and preferably has a wavelength of ultraviolet light of 180 to 320 nm. The ultraviolet irradiation may be performed at any time during the stretching step of the substrate, during the heat fixing, or after the heat fixing. Regarding the method of irradiating ultraviolet rays, a high-pressure mercury lamp having a main wavelength of 365 nm can be used if there is no problem that the surface temperature of the substrate rises to about 150 ° C. When low-temperature treatment is required, a low-pressure mercury lamp having a main wavelength of 254 nm is preferred. It is also possible to use an ozone-less high-pressure mercury lamp and a low-pressure mercury lamp. Regarding the amount of processing light, as the amount of processing light increases, the adhesive strength between the substrate and the layer to be adhered improves, but there is a problem that the substrate is colored and the substrate becomes brittle as the amount of light increases. Therefore, a normal high pressure mercury lamp having a main wavelength of 365 nm is applied to a plastic film of polyester, polyolefin or the like with an irradiation amount of 20 to 10000.
(MJ / cm ² ), more preferably 50 to 2000 (mJ / cm ² ).
/ Cm ² ). In the case of low-pressure mercury lamp for a 254nm main wavelength, the irradiation light amount 100~10000 (mJ / cm ²⁾ C., more preferably 300~1500 (mJ / cm ^2).

Next, glow discharge treatment, which is one of the effective surface treatments, can be performed by any of the conventionally known methods, for example, Japanese Patent Publication Nos. 35-7578, 36-10336, and 4
Nos. 5-22004, 45-22005 and 45-2
No. 4040, No. 46-43480, U.S. Pat.
7,792, 3,057,795, 3,17
9,482, 3,288,638, 3,30
9,299, 3,424,735, 3,46
No. 2,335, No. 3,475,307, No. 3,76
1,299, British Patent 997,093,
No. 129262 can be used. In particular, a glow treatment is particularly effective as a surface treatment that simultaneously satisfies the required adhesiveness, yellowing suppression, and blocking prevention required for the substrate of the present invention. The glow discharge treatment is preferably performed while introducing various gases such as oxygen, nitrogen, helium or argon into the atmosphere. Furthermore, when steam is introduced, it has an adhesive effect equal to or higher than that of the case of introducing a special gas, the price is significantly lower, and it is an industrially superior method.

When the glow discharge treatment is performed in the presence of water vapor, the partial pressure of water vapor is preferably 10% or more and 100% or less, more preferably 40% or more and 90% or less. The gas other than water vapor is air composed of oxygen, nitrogen and the like. Further, when vacuum glow discharge treatment is performed in a state where the film to be surface-treated is heated in advance, the adhesiveness can be improved in a shorter time than when treated at room temperature, and yellowing can be greatly reduced. The preheating temperature is preferably 50 ° C. or higher. As a specific method of raising the polymer surface temperature in a vacuum,
There are heating by an infrared heater, heating by contact with a heat roll, and the like. For example, if one wishes to preheat the film surface to 80 ° C, it is sufficient to contact the film with a hot roll at 80 ° C for at most 1 second. The heating method is not limited to the method described above, and a widely known heating method can be used.

The preheated substrate is subjected to glow discharge treatment. Important treatment conditions include the degree of vacuum, voltage between electrodes, discharge frequency, and the like. The pressure during glow discharge treatment is 0.005 to
It is preferably 20 Torr, more preferably 0.02
~ 2 Torr. The voltage is preferably between 500 and 5000 V, more preferably between 500 and 3000 V. Further, the discharge frequency used is from DC to several 1000 MHz, preferably 50 Hz as seen in the prior art.
20 MHz, more preferably 1 KHz-1 MHz. The discharge treatment intensity is 0.01 KV · A · min / m ² -5
KV · A · min / m ² is preferred, and more preferably 0.15
Adhesion performance was excellent KV · A · min / m ² ~1KV · A · min / m ² is obtained. It is preferable that the temperature of the substrate subjected to the glow discharge treatment is immediately lowered by using a cooling roll. The substrate tends to be plastically deformed by an external force accompanying the rise in temperature, and the flatness of the substrate to be processed is impaired. Furthermore, a low molecular weight substance (monomer, oligomer, etc.) may precipitate on the surface of the substrate and deteriorate transparency and blocking resistance.

Next, the corona discharge treatment will be described by any of the conventionally known methods, for example, JP-B-48-5043,
JP-A-47-51905, JP-A-47-28067, JP-A-49-83767, JP-A-51-41770, and JP-A-51-51770.
This can be achieved by a method disclosed in, for example, JP-A-131576. The discharge frequency is suitably from 50 Hz to 5000 KHz, preferably from 5 KHz to several hundred KHz, and particularly preferably from 10 Hz to 30 KHz. If the discharge frequency is too low, stable discharge cannot be obtained, and pinholes are formed on the object to be processed, which is not preferable. On the other hand, if the frequency is too high, a special device for impedance matching is required, and the device becomes expensive, which is not preferable. Regarding the treatment intensity of the object to be treated, usually, 0.001 KV · A · min /
m ² -5 KV · A · min / m ² , preferably 0.01 KV · A
Min / m ^{2 to 1} KV · A · min / m ² is appropriate. The gap clearance between the electrode and the dielectric roll is 0.5-2.5m
m, preferably 1.0 to 2.0 mm. As a corona discharge treatment machine, a solid state corona treatment machine 6KVA model manufactured by Pillar can be used.

For the flame treatment, natural gas, liquefied propane gas or the like can be used, and the mixing ratio with air is important. A preferred gas / air mixing ratio is a volume ratio, for propane, 1/14 to 1/22, more preferably 1/16 to 1
/ 19. For natural gas, the ratio is 1/6 to 1/10, more preferably 1/7 to 1/9. Flame throughput is 1-5
0 Kcal / m ² , more preferably 3 to 20 Kcal / m ²
It is. In addition, the distance between the tip of the inner flame of the burner and the substrate is 4c.
m is more effective. As the processing device, a frame processing machine manufactured by Kasuga Electric Co., Ltd. can be used. The backup roller supporting the substrate during processing is preferably a hollow roller, and it is preferable that the cooling liquid is passed through the roller to keep the temperature constantly constant.

Next, in the present invention, in order to increase the surface hardness, it is preferable to provide a hard coat on the undercoat layer as required. As the hard coat material, a known curable resin is preferably used, and a thermosetting resin, a radiation-curable resin and the like are preferable among them. Examples of the thermosetting resin include those utilizing a crosslinking reaction of a prepolymer such as a melamine resin, a urethane resin, and an epoxy resin. Examples of the radiation-curable resin include polyfunctional monomers, such as radiation represented by polyfunctional acrylate or methacrylate (for example, pentaerythritol tetra (meth) acrylate or dipentaerythritol hexa (meth) acrylate), particularly ultraviolet light. Curable compounds. It is preferable to add a polymerization initiator to these compounds as needed. Also,
It is particularly effective to include a filler in the hard coat layer for the purpose of increasing hardness and enhancing scratch resistance, and examples thereof include fine particles of an oxide such as silica, alumina, and zirconia, and colloidal particles. The particle size of the fine particles as these fillers is 1 to 100 nm.
Is preferably added in an amount of at least 5% by volume of the curable resin.
0 vol% or less is preferable. If the content is 50% by volume or more, the film becomes brittle, and if the content is too small, the added effect cannot be obtained. The thickness of the hard coat layer is preferably 2 to 30 μm, and 4 to 10 μm.
m is particularly preferred. Further, if necessary, an anionic, cationic or nonionic surfactant is added, or a surface treatment such as a corona treatment or a glow treatment is performed to improve the hydrophilicity and adhesion of the surface of the hard coat, and to form a conductive layer. The coatability and the adhesion to the conductive layer can be improved.

Specific examples of the surfactant used in the undercoat layer and the hard coat layer are described below, but are not limited thereto (here, -C ₆ H _4- represents a phenylene group). . _{WA-1: C 16 H 33} (OCH 2 CH 2) 10 OH WA-2: C 9 H 19 -C 6 H 4 - (OCH 2 CH 2) 12 O
H WA-3: sodium dodecylbenzene sulfonate WA-4: sodium tri (isopropyl) naphthalene sulfonate WA-5: sodium tri (isobutyl) naphthalene sulfonate WA-6: sodium dodecyl sulfate WA-7: di-α-sulfosuccinate (2-ethylhexyl) ester sodium salt _{WA-8: C 8 H 17} -C 6 H 4 - (CH 2 CH 2 O) 3 (CH 2) 2 S
O ₃ K

WA-10: Cetyltrimethylammonium chloride WA-11: C₁₁H_{twenty three}CONHCH_TwoCH_TwoN⁽⁺⁾(CH_Three)_Two-CH2COO^(-) WA-12: C₈F₁₇SO_TwoN (C_ThreeH₇) (CH_TwoCH
_TwoO)₁₆H WA-13: C₈F₁₇SO_TwoN (C_ThreeH₇) CH2COOK WA-14: C₈F₁₇SO_ThreeKWA-15: C₈F₁₇SO_TwoN (C_ThreeH₇) (CH_TwoCH
_TwoO)_Four(CH_Two)_FourSO_ThreeNa WA-16: C₈F₁₇SO_TwoN (C_ThreeH₇)-(CH_Two)_Three-OC
H_TwoCH_Two-N⁽⁺⁾(CH_Three) _Three・ CH_Three-C₆H_Four-SO_Three ^(-) WA-17: C₈F₁₇SO_TwoN (C_ThreeH₇) CH_TwoCH_TwoCH_Two
N⁽⁺⁾(CH_Three)_Two-CH_TwoCOO^(-)

Next, the conductive layer of the present invention is characterized by containing at least one kind of silver colloid. The conductive layer has a resistance of 10 KΩ (applied voltage of 90 V) or less. In the present invention, an alloy of silver and palladium is more preferable from the viewpoint of weather resistance, and the content of palladium is preferably 5 to 30 wt%. Examples of a method for producing the silver colloid particles include a method for producing fine particles by a normal low vacuum evaporation method and a method for producing a metal colloid for reducing an aqueous solution of a metal salt. The average particle size of these metal particles is 1 to 200 nm, more preferably 1 to 100 n.
m, particularly preferably 2 to 80 nm. The conductive layer is preferably substantially composed of only metal fine particles, and preferably does not contain a nonconductive material such as a binder from the viewpoint of conductivity.

The formation of the conductive layer composed of the silver colloid particles is as follows.
It can be prepared by applying a coating liquid in which metal particles are dispersed in an aqueous solution or an organic solvent or the like on a substrate. An aqueous solution of the silver colloid particles is preferable, but as a water-soluble solvent miscible with water, ethyl alcohol, n-propyl alcohol, i-propyl alcohol, 1-butyl alcohol,
Alcohols such as 2-butyl alcohol, t-butyl alcohol, methyl cellosolve and butyl cellosolve are preferred. The application amount of these metals is 50 to 150 mg
/ M ² is preferable. If the coating amount is small, excellent conductivity cannot be obtained, and even if the coating amount is increased, the effect of improving the conductivity is reduced. The resistance of the conductive layer itself is preferably 10 KΩ or less, more preferably 5 KΩ or less under the condition of an applied voltage of 90 V, and particularly preferably 1 KΩ or less to obtain a good electromagnetic wave shielding effect.

In the present invention, a protective layer for a conductive layer is preferably used. The material used for the protective layer in the present invention is not particularly limited as long as it is for protecting the conductive layer. Among them, preferred materials are, for example, polyisoprene, chlorosulfonated polyethylene, polysulfide rubber, fluororubber, casein, phenol resin, polysulfide epoxy resin, urea resin, melamine resin, nylon 6, nylon 66, polymethyl methacrylate , Ethyl acrylate / ethylene copolymer, polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, (mono-, di-, tri-) acetylcellulose, nitrocellulose, polyethylene, polypropylene, polybutylene, polystyrene,
Examples include SBR resin, polyacrylonitrile, and copolymers and mixtures thereof.

Among these resins, preferred resins include fluoro rubber, phenol resin, urea resin, melamine resin, nylon 6, nylon 66, polymethyl methacrylate, polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, and polyvinyl formal. , (Mono,
Examples thereof include di-, tri-) acetyl cellulose, nitrocellulose, and radiation (ultraviolet rays, electron beams, X-rays, etc.) curable resins. Among them, in the present invention, particularly preferably, a resin prepared from a polyfunctional vinyl derivative of a polyol (such as a meta (acrylate) polyester) and polymerized by radiation, such as trimethylolpropane tri (meth) acrylate and pentaerythritol tetra (meth) Acrylate and dipentaerythritol hexa (meth) acrylate are exemplified. A polymerization initiator can be added to these radiation curable resins as needed.

The thickness of the protective layer for a conductive layer of the present invention is not particularly limited, but is preferably from 10 to 5000 nm, more preferably from 20 to 2000 nm, further preferably from 20 to 1000 nm. 30-500 nm
It is. The thinner the film is, the more the surface resistance can be obtained from above the protective layer, which is preferable. Therefore, the resistance measured via the protective layer surface is preferably 10 KΩ or less (90 V applied voltage), more preferably 5 KΩ or less, and particularly preferably 1 KΩ or less. In particular, when the protective layer thickness is 500 nm or less, the applied voltage is 10 V
However, a surface resistance of 1 kΩ or less can be obtained. The protective film for a conductive layer of the present invention can also exhibit a function as an antireflection layer by controlling the refractive index. At least one transparent antireflection layer provided with the resin having a refractive index different from that of the transparent conductive layer has a refractive index of 1.
It is preferably smaller than 6. When the refractive index is 1.6 or more, the reflectance increases and the antireflection effect decreases.

The protective layer for a conductive layer may be added with a metal oxide as needed. Specifically, silica,
Oxides such as alumina, zirconia, and titania can be given. These oxides increase the film strength,
It is added to change the refractive index. Further, an overcoat layer can be provided further outside the protective film. As a specific example of forming the overcoat layer, a known fluorine-containing low surface energy compound is preferable, and specific examples thereof include a fluorocarbon-containing silicon compound and a fluorocarbon-containing polymer. . These compounds can be added not only to the overcoat layer but also to the protective film.

The conductive film of the present invention is produced by dipping a coating solution of each layer on an undercoated base film,
Each layer can be sequentially formed by a known thin film coating method such as a spinner method, a spray method, a blade method, a roll coater method, a wire bar method, or the like, or simultaneously multi-layer coated, and dried. As a method for forming each thin film, a method using a wire bar is preferable. The transparent conductive film of the present invention is not particularly limited as long as it is dark and cannot withstand use when viewing a display device in terms of its transparency, but preferably has a visible light transmittance of 40% or more, and preferably 50% or more. The above is more preferred, and the proportion is particularly preferably 60% or more. The reflectance of the transparent conductive film is preferably as small as possible, preferably 1% or less, particularly preferably 0.7% or less. When the transparent conductive film of the present invention is used as a protective layer of an electronic image forming material, it is preferable that an adhesive layer be provided on the side opposite to the conductive layer and bonded to the surface of the image forming material.
It is also preferable to use the double-sided tape to bond the transparent conductive film of the present invention to an electronic image forming material. Hereinafter, the present invention will be described more specifically with reference to Examples, but it should not be construed that the invention is limited thereto.

[0031]

Examples (Example 1) (1) () Preparation of Substrate 1-1) Surface Treatment of Substrate Surface treatment of a substrate (175 μm thick) was performed on both surfaces of the substrate according to Table 1. The conditions of each process are as follows.

A) UV treatment Using a high-pressure mercury lamp of 365 nm, a surface temperature of 75
C., and irradiation was performed at an irradiation light amount of 1000 mJ / cm ² for 3 minutes. After the irradiation, the temperature was lowered to 30 ° C. or lower by a cooling roller to prepare a substrate that had been subjected to ultraviolet treatment.

B) Glow treatment Four rod-shaped electrodes each having a cross section having a diameter of 2 cm and a length of 150 cm and having a hollow portion serving as a coolant flow passage were fixed at an interval of 10 cm in an insulating plate shape. This electrode plate was fixed in a vacuum, and further, the substrate was transported so as to be 15 cm away from the electrode and face the electrode directly to the surface, and subjected to a surface treatment for 2 seconds. Immediately before the substrate passed through the electrode, the substrate was heated with a heating roller at a temperature equal to or lower than the Tg of the substrate. The vacuum was 0.2 Torr, and the H2O partial pressure was 75%.
The discharge frequency was 30 KHz, the output was 2500 W, and the treatment intensity was 0.5 KV · A · min / m ² . After the treatment, the substrate was cooled to 30 ° C. and subjected to a glow treatment to prepare a substrate.

C) Corona treatment Corona discharge treatment is carried out using a solid state corona treatment machine 6KVA model manufactured by Pillar Co., Ltd.
/ Min. At this time, the object to be processed was processed at 0.375 KV · A · min / m ^{2 based on} the current and voltage readings. The discharge frequency during the treatment was 9.6 KHz, and the gap clearance between the electrode and the dielectric roll was 1.6 mm.

D) Flame treatment Using liquefied propane gas and a gas having an air ratio of 1/5, 1
The surface of the substrate was subjected to a flame treatment so as to be 0 Kcal / m ² . At this time, the distance between the tip of the inner flame of the burner and the substrate is 5c.
m. In the flame treatment, cooling water was flowed inside the backup roller, and the substrate was surface-treated while being kept at 30 ° C.

1-2) Undercoating As described in Table 1, the following undercoating coating solution-A or undercoating coating solution-B was applied to both sides of the substrate and dried to perform an undercoating treatment.

(Undercoating coating solution-A) 5 parts by weight of acrylic resin (HA-16, manufactured by Nippon Acrylic Co.) 2.5 parts by weight of acrylic-modified copolymerized polyester resin (Veslegin A-51 5G manufactured by Takamatsu Resin) Butadiene Styrene copolymer latex (30/70 by weight) 2.5 parts by weight Melamine resin (Sumitex Resin M-3 manufactured by Sumitomo Chemical Co., Ltd.) 2.5 parts by weight Colloidal silica (Sno-Tex ZL manufactured by Nissan Chemical Industries) 0. 04 parts by weight ・ WA-2 0.2 parts by weight ・ WA-8 0.1 parts by weight ・ 2,4-dichloro-6-hydroxy-S-triazine 0.5 parts by weight ・ Epichlorohydrin resin 0.1 parts by weight ・ Water It was added so as to be 100 parts by weight in total.

(Undercoat coating solution-B) 7 parts by weight of phenol / formalin condensate 2.5 parts by weight of diglycidyl ether of triethylene glycol 0.2 parts by weight of silica particles (particle size: 20 nm) WA-10 .05 parts by weight ・ Methyl isobutyl ketone 90.25 parts by weight

(Undercoat Coating Solution-C) Chloroprene rubber 10 parts by weight Zinc oxide / aluminum oxide 0.5 / 0.5 parts by weight Resorcin / formalin condensate 3 parts by weight WA-2 0.05 parts by weight 86 parts by weight of toluene / methyl acetate (1/1)

(Undercoat coating solution-D) 5 parts by weight of equimolar polycondensate of phthalic acid and adipic acid and ethylene glycol and neopentyl glycol 5 parts by weight of WA-2 0.05 parts by weight of toluene / methyl acetate (1/1) ) 94.95 parts by weight

These undercoat coating solutions were applied by a 7 ml / m ² bar coater, and were conveyed at 160 ° C. in a heating zone.
For 5 minutes. Immediately before the winding, the substrate was cooled to 30 ° C. or less with a cooling roller, and the prepared undercoated substrate was wound.

(2) Preparation of Hard Coat Layer Coating Solution: 2-1) Surface Treatment of Silica Fine Particles 200 g of a 40% by weight methanol dispersion of silica fine particles having an average particle diameter of 15 nm was placed in a stirrer, a thermometer and a reflux condenser. Was placed in a 500 ml glass three-necked flask equipped with. 0.2 g of 2N hydrochloric acid was added thereto, and the temperature was raised to 60 ° C. under a nitrogen stream. Then, 10 g of 3-methacryloyloxypropyltrimethoxysilane was added, and stirring was continued for 4 hours to perform a surface treatment on the silica fine particles.

2-2) Preparation of Coating Solution for Hard Coat Layer 97 g of methanol, 163 g of isopropanol and 163 g of butyl acetate were added to 116 g of a 43% by weight methanol dispersion of silica fine particles surface-treated in 2-1).
To the mixture, 200 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPHA, manufactured by Nippon Kayaku Co., Ltd.) was added and dissolved. A photopolymerization initiator (Irgacure 9) was added to the obtained solution.
07, Ciba-Geigy) 7.5 g, and a photosensitizer (Kayacure DETX, Nippon Kayaku Co., Ltd.) 5.0 g
Was added and dissolved. After stirring the mixture for 30 minutes, the mixture was filtered with a polypropylene filter having a pore size of 1 μm to prepare a coating solution for a hard coat layer.

[0044] (3) the coating liquid for a conductive layer 3-1) Adjustment of 30% iron sulfate silver colloidal dispersion _{(II) FeSO 4 · 7H 2} O, adjust the 40% citric acid, mixed, held at 20 ° C. While stirring, a solution of 10% silver nitrate and palladium nitrate (mixed at a molar ratio of 9/1) was added and mixed at a rate of 200 ml / min, and then the resultant was repeatedly washed with water by centrifugation.
Pure water was added so that the final concentration was 3% by weight to prepare a silver-palladium colloidal dispersion. The particle size of the obtained silver colloid particles, which are the conductive particles of the present invention, is about 9 to 1 by TEM.
It was 2 nm. As a result of measurement by fusion bonding high frequency plasma (ICP), the ratio of silver to palladium was 9/1, which was the same as the charged ratio.

3-2) Preparation of Silver Colloid Coating Solution To 100 g of the silver colloid dispersion liquid, isopropyl alcohol was added, and the mixture was ultrasonically dispersed and filtered with a polypropylene filter having a pore size of 1 μm to prepare a coating solution.

(4) Preparation of Coating Solution for Conductive Layer Protective Layer 4-1) UV Cured Film Composition A A mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (DPH)
A, 2 mg of photopolymerization initiator (Irgacure 907, Ciba-Geigy) 80 mg and photosensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) per 2 g
30 mg of methyl isobutyl ketone / 2-
A mixed solution of butanol / methanol (2/2/1) was dissolved. The dissolution concentration was changed to a predetermined thickness, the mixture was stirred for 30 minutes, and then filtered through a polypropylene filter having a pore size of 1 μm to prepare a coating solution for a conductive layer protective layer.

(5) Preparation of Transparent Conductive Film A base having at least one of (1) provided with an undercoat layer is provided on the substrate.
C prepared in 2-2) using a bar coater on the surface of
Apply and dry hard coat coating liquid to a layer thickness of 8 μm
Then, ultraviolet irradiation was performed to produce a hard coat layer. This har
After the corona treatment on the surface of the coated layer, the conductive layer coating solution
With a bar coater to apply 70mg / m ^TwoTo be
Coated and dried at 40 ° C. On this conductive layer coating surface,
Spray the water sent by the pump and excess with an air knife
After removing the water, transport in a heating zone at 120 ° C.
5 minutes. Silver colloid applied amount is 75m
g / m^TwoMet. And then on this conductive layer,
Apply the coating solution for conductive layer protective film prepared in (4)
Irradiate ultraviolet rays for 2 minutes with P647-GA manufactured by this screen company.
To cure the protective layer.
Lum created.

(6) Evaluation The obtained transparent conductive film was evaluated by the following method. 6-1) Surface Resistance The sample was conditioned at 25 ° C. and 10% for 6 hours, and its resistance was measured using a four-terminal method surface resistivity meter (“Loresta GP” manufactured by Mitsubishi Chemical Corporation). Smaller is more preferable. 6-2) Transmittance Spectrophotometer (UV-2400P) manufactured by Shimadzu Corporation
The average transmittance at a wavelength of 400 to 800 nm was measured using C). 6-3) Scratch Resistance A 150 g load was applied to steel wool (3 cm square) to rub its surface, and the state of scratches on the surface was visually evaluated. A: No scratches were recognized B: Slight scratches were recognized C: Scratches were considerably recognized D: Scratch was significantly recognized 6-4) Adhesiveness The sample was subjected to 6 at 25 ° C. and 60% RH environment. After humidifying for time, the surface is cross-cut with a cutter (NT cutter) to a depth of 1.5 mm
Individual cut pieces were formed. Next, the cells were aged for 7 days in an oven at 50 ° C. and 95% RH, and then aged for 7 days in an oven at 10 ° C. and 10% RH. Manufactured), and the tape was vigorously peeled off by hand after standing for 2 hours.
This peeling test was repeated five times in total, and the number of stripped sections was evaluated. The more peeled sections, the worse the adhesion.

(6) Results The properties of the present invention and comparative properties are shown in Table 1. Comparative Sample 01 having no undercoat layer was excellent in resistance and transmittance, but was very poor in scratch resistance and adhesiveness. In contrast, Sample 02 of the present invention provided with the undercoat layer of the present invention
No.-05 were excellent in all of resistance, transmittance, scratch resistance and adhesiveness. Further, the sample 1 of the present invention, which had been subjected to a surface treatment of the substrate before the undercoating layer was performed in the present invention.
Nos. 0 to 16 were found to have higher levels of adhesion than the undercoat layer alone. this is,
It is presumed that the undercoat layer and the surface treatment acted synergistically. On the other hand, comparative samples 06 to 09 subjected to only surface treatment
Is an insufficient level in a severe adhesion test, and is a practical problem when subjected to environmental conditions of high temperature and high humidity and low temperature and low humidity. From the above, it is clear that the present invention is excellent in all respects, and is the result of intensive research.

[0050]

[Table 1]

(Example 2) Sample 02 of the present invention of Example 1
(10 × 10 cm ² ) A copper foil was adhered to the diagonal surface with a conductive tape (carbon black adhesive tape), and the resistance between the copper foils drawn from the film was measured with a tester. It was confirmed that it had conductivity.

(Example 3) In the same manner as in the sample 02 of the present invention in Example 1, except that a fluororesin was further applied to the outside of the protective layer with a solution mainly composed of a MEK solvent, and an overcoat layer of 100 nm was provided. Sample 32 of the present invention was prepared in exactly the same manner as Sample 02. Resistance is 270Ω, transmittance 63
%, And the scratch resistance was A, indicating that the scratch resistance was improved as compared to Sample 03. This indicates that the overcoat layer can impart more excellent properties in the present invention.

(Example 4) A sample 42 of the present invention was prepared in exactly the same manner as in the sample 02 of the present invention except that the conductive layer was formed of colloidal gold particles.
The resistance was 250 Ω, the transmittance was 61%, the scratch resistance was A and B, and the adhesiveness was 13. However, this sample 42
Although metal reflectivity was slightly observed as compared with Sample 02, it did not impair the commercial value.

(Example 5) In the sample 02 of the present invention of Example 1, an undercoat D was applied on the side opposite to the side having the conductive layer to form an adhesive layer. Further, a polyethylene sheet (20 μm thick) was bonded thereon. The characteristics of the obtained sample 52 were exactly the same as those of the sample 02. Thereby, the transparent conductive film of the present invention can be used as a protective film for various electronic material screens. In particular, when the polyethylene sheet was peeled off before bonding the polyethylene sheet to the flat CRT and the transparent conductive film was bonded to the glass plate, a CRT excellent in dust and scratches could be produced.

[0055]

The present invention provides a film having a simple layer structure.
A film having low surface resistance and excellent in transparency, scratch resistance and adhesiveness can be obtained. As a result, grounding can be performed directly from the surface, and a transparent conductive film can be obtained by a simple method.

[Brief description of the drawings]

FIG. 1 is a schematic view of a configuration of an antireflection transparent conductive laminated film of the present invention.

[Explanation of symbols]

 Reference Signs List 1 transparent substrate 2 hard coat layer 3 transparent conductive layer 4 protective layer for conductive layer

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01Q 17/00 H05K 9/00 V H05F 1/00 G02B 1/10 A H05K 9/00 Z F term (reference) ) 4F100 AA20H AB24B AK01A AK01C AK25 AK33 AK36 AK41 AK73 AL05 AS00D BA03 BA04 BA05 BA10A BA10B BA10D CA18C CA23 CA30C CC00C CC00E DE01B EJ54A EJ55A EJ64A GB41 JB05C JB06C JG01B JK06 JK12E JK16 JM10B JN01 YY00B 5E321 AA04 BB25 BB32 BB44 CC16 GG01 GG05 GH01 5G067 AA14 AA53 BA02 CA03 CA05 DA02 5G307 FA02 FB02 FC01 FC05 5J020 BD01 BD04

Claims (11)

[Claims] 1. A transparent conductive film having at least one conductive layer on one side of a base material, wherein the base material has at least one undercoat layer on the conductive layer side of the base material, and the conductive layer has a particle size of 1 to 3. A transparent conductive film, which is a layer containing 200 nm colloidal silver particles. 2. The transparent conductive film according to claim 1, wherein the undercoat layer of the substrate is a layer containing at least one of a hydrophobic polymer and a hydrophilic polymer. 3. The transparent conductive film according to claim 1, wherein the undercoat layer of the base material contains at least one surfactant. 4. The transparent conductive film according to claim 1, wherein the undercoat layer of the base material contains at least one hardener. 5. The transparent conductive film according to claim 1, wherein the substrate is subjected to a surface treatment before applying the undercoat layer of the substrate. 6. The transparent conductive film according to claim 1, wherein the surface treatment of the substrate is an ultraviolet treatment, a glow discharge treatment, a corona discharge treatment, or a flame treatment. 7. The resistance of the conductive layer is 10K at 90V applied voltage.
The transparent conductive film according to any one of claims 1 to 6, wherein the value is Ω or less. 8. The transparent conductive film according to claim 1, wherein the silver colloid contains 1 to 30% by weight of palladium. 9. The transparent conductive film according to claim 1, further comprising at least one protective layer outside the conductive layer. 10. The transparent conductive film according to claim 1, wherein the substrate is a plastic film having a hard coat layer. 11. A grounding method, wherein a ground is provided by directly attaching a conductive tape to the surface of the conductive film according to claim 1.