JPH11107160A - Transparent electroconductive fiber, transparent material for shielding electromagnetic wave and their production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a transparent electroconductive fiber having a high electroconductivity and excellent transparency, to provide a production method thereof, and to obtain a transparent material for shielding electromagnetic waves and to provide a method for producing the transparent material for shielding the electromagnetic waves. SOLUTION: This transparent electroconductive fiber is the one obtained by coating the surface of a glass fiber with a metal oxide thin membrane, and the metal oxide thin membrane has >=70% total light transmittance and >=10<-1> Ωcm specific resistance. The transparent material for shielding electromagnetic waves is obtained by allowing a resin having >=70% total light transmittance to include the transparent electroconductive fibers in the interior thereof and/or on the surface thereof so that the transparent electroconductive fibers may electrically keep contact with each other, and has >=60% total light transmittance. A production method thereof is also proposed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent conductive fiber having high conductivity and excellent transparency, a method for producing the same, and a transparent electromagnetic wave shielding material utilizing the same and a method for producing the same.

[0002]

2. Description of the Related Art Conductive fibers are added to a resin as a filler for imparting conductivity to a resin molded product or the like, and are used for the purpose of preventing dust from adhering to electronic parts, preventing electrostatic interference, shielding electromagnetic waves, and the like. in use. Conventionally, as such conductive fibers, inorganic fibers such as carbon fibers and metal fibers; fibers in which the surface of the fibers is coated with a metal, and the like are used. It could not be used where needed.

Glass fibers are conceivable as transparent fibers having conductivity. To impart conductivity so as not to impair the transparency of glass fibers, an alkali metal is added and conductivity is imparted by ionic conductivity. However, this has not yet been achieved to obtain sufficient conductivity.

In recent years, with the development of OA equipment and other electronic equipment, in order to prevent noise and malfunction of electronic equipment and to prevent the influence of electromagnetic waves on the human body, a material having an electromagnetic wave shielding effect and being transparent is desired. I have. These are provided for use as filters for various displays, viewing windows for shielded rooms of electronic equipment, and the like.

Heretofore, as such a visible electromagnetic wave shielding material, a conductive metal oxide or a metal coated with a transparent material, a conductive synthetic fiber net, a wire net made of stainless steel, and the like have been used. None of them had sufficient strength or electromagnetic wave shielding effect.

Japanese Patent Publication No. 2-60496 discloses a technique in which a metal-plated synthetic fiber gauze is buried in an acrylic resin molded body to form a transparent electromagnetic wave shielding material. However, since metal-plated synthetic fiber gauze itself is not transparent, there is a limit in transmitting light even if the fiber is made thin.
The visibility of the display device seen through this was low, and it was not suitable for shielding electromagnetic waves of displays and instruments.

On the other hand, as an electromagnetic wave shielding material having excellent transparency, there are a glass plate, a transparent resin sheet, a transparent resin film, etc. provided with a transparent conductive metal oxide layer by vapor deposition, sputtering or the like. However, the glass plate provided with the transparent conductive metal oxide layer is heavy in weight, is difficult to be formed into various shapes, and has a risk of being damaged. was there.

Further, the transparent resin is lighter than glass,
It is easy to mold and hard to break, but when a transparent conductive metal oxide layer is provided directly on the transparent resin by vapor deposition, sputtering, etc., due to the difference in thermal expansion between the transparent resin and the metal oxide layer,
Cracks are formed in the metal oxide layer, the layer becomes discontinuous, and there is a defect that an electromagnetic wave shielding effect cannot be obtained. Furthermore, sputtering and vapor deposition are disadvantageous in that they are vacuum processes, have low productivity, and require expensive equipment.

[0009]

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide a transparent conductive fiber having high conductivity and excellent transparency, a method for producing the same, a transparent electromagnetic wave shielding material using the same, and a transparent electromagnetic wave shielding material using the same. It is intended to provide a manufacturing method.

[0010]

According to a first aspect of the present invention, there is provided a transparent conductive fiber comprising a glass fiber surface coated with a metal oxide thin film. Has a total light transmittance of 70% or more and a specific resistance of 10
^-1 Ωcm or less, which is a transparent conductive fiber. Hereinafter, the present invention will be described in detail.

The transparent conductive fiber of the present invention 1 is obtained by coating the surface of a glass fiber with a metal oxide thin film. As the glass fiber, known materials can be used, and a material suitable for being coated with the metal oxide thin film is preferably used. As such a material, for example, E glass or the like having a small alkali content is used, and a material which does not contain light scattering bubbles or foreign matter is preferably used.

Further, in order to prevent the diffusion of alkali metal ions into the metal oxide thin film, a coating such as SiO ₂ may be previously provided on the glass fiber by a known method. The glass fiber preferably has a diameter of 1 to 100 μm, and may be a short fiber or a long fiber.

The metal oxide thin film used in the present invention 1 is
The total light transmittance is 70% or more, and the specific resistance is 10 ^-1 Ωc.
m or less. When the total light transmittance is less than 70%, the transparency of the obtained transparent conductive fiber is impaired, so that the above range is limited. The specific resistance is 10 ^-1 Ωcm
If it exceeds, the electromagnetic wave shielding effect of the obtained transparent conductive fiber is impaired, so that it is limited to the above range.

The metal oxide thin film is not particularly limited as long as it has a total light transmittance of 70% or more and a specific resistance of 10 ^-1 Ωcm or less. For example, tin is added to indium oxide. Examples include ITO, ATO in which antimony is added to tin oxide, and AZO in which aluminum is added to zinc oxide. The thickness of the metal oxide thin film is preferably from 100 to 5000 °. If it is less than 100 °, the conductivity is not sufficient, and if it exceeds 5000 °, cracks tend to occur.

Various methods can be adopted as the method for producing the transparent conductive fiber of the present invention 1.
It can be manufactured by providing a transparent conductive metal oxide thin film on a glass fiber by a sputtering method. In the above sputtering method, a glass fiber is set in a chamber using a metal oxide target as a raw material, and a film is formed under reduced pressure. that time,
In order to form a uniform thin film on the glass fiber, it is preferable to form the film while rotating the glass fiber in a chamber of a sputtering apparatus. As a sputtering method, a known method may be used, and a film forming method by a CVD method using plasma, laser, or the like may also be used.

According to a second aspect of the present invention, there is provided a method for producing the transparent conductive fiber according to the first aspect of the present invention, wherein a solution of a metal oxide precursor is applied to the surface of a glass fiber, and the solution is then treated. A method for producing a transparent conductive fiber, comprising forming an oxide thin film. This method does not require expensive equipment and is excellent in productivity.

In the above method, first, a solution in which a compound (metal oxide precursor) which is a precursor of a metal oxide is dissolved is used as a coating solution, and this coating solution is applied to the surface of the glass fiber.

The above-mentioned coating solutions can be prepared from soluble compounds of the respective metal elements. For example, in order to obtain thin films of ITO in which tin is added to indium oxide, ATO in which antimony is added to tin oxide, and AZO in which zinc is added to aluminum, alkoxides, chlorides, nitrates, and organic acids of the corresponding metals are respectively provided. A solution of a salt, a complex, or the like is used as the coating solution. With these coating solutions, a metal oxide thin film composed of an ITO film, an ATO film, an AZO film, or the like can be obtained.

The coating solution for obtaining the above-mentioned ITO film comprises at least one selected from the group consisting of indium alkoxide, indium chloride, indium nitrate, indium organic acid and indium complex, and tin alkoxide, tin chloride and tin organic acid. And at least one selected from the group consisting of tin complexes in a solvent such as alcohol or water.

The indium alkoxide is not particularly restricted but includes, for example, indium trimethoxide, indium triethoxide, indium tri-n-propoxide, indium tri-i-propoxide, indium tri-n-butoxide, indium sec-butoxide, Indium t-butoxide and the like can be mentioned. The indium chloride is not particularly limited, and may be a hydrate or an anhydride.

The indium nitrate is not particularly limited, and may be a hydrate or an anhydride. The organic acid indium is not particularly limited, and includes, for example, indium acetate, indium 2-ethylhexanoate, and the like. The indium complex is not particularly limited,
For example, triacetylacetone indium and the like can be mentioned.

The above-mentioned tin alkoxide is not particularly restricted but includes, for example, tin tetramethoxide, tin tetraethoxide, tin tetra n-propoxide, tin tetra i-propoxide, tin tetra n-butoxide, tin tetra sec-butoxide. , Tin tetra-t-butoxide and the like. The tin chloride is not particularly limited, for example, stannous chloride,
Stannous chloride, and hydrates and anhydrides thereof, and the like can be mentioned. Further, a chloride having an organic functional group such as butyltin chloride may be used.

The organic acid tin is not particularly limited, and examples thereof include tin oxalate, tin 2-ethylhexanoate, di-n-butyltin diacetate, and di-n-butyltin dilaurate. The tin complex is not particularly limited, and examples thereof include diacetylacetone dibutyltin.

The coating solution for obtaining the above-mentioned ATO film comprises at least one selected from the group consisting of tin alkoxide, tin chloride, tin nitrate, organic acid tin, and tin complex, and antimony alkoxide, antimony chloride, and antimony complex. It can be prepared by dissolving at least one selected from the group consisting of a solvent such as alcohol and water.

The above-mentioned tin alkoxide, tin chloride, tin nitrate, organic acid tin, and tin complex include those similar to those described above. The above-mentioned antimony alkoxide is not particularly limited. t-butoxide and the like. The antimony chloride is not particularly limited, and examples thereof include antimony trichloride and antimony pentachloride. The antimony complex is not particularly limited, and examples include diacetylacetone antimony.

The coating solution for obtaining the AZO film is at least one selected from the group consisting of zinc alkoxide, zinc chloride, zinc nitrate, zinc organic acid, and zinc complex.
Species and aluminum alkoxide, aluminum chloride,
It can be prepared by dissolving at least one selected from the group consisting of aluminum nitrate, organic acid aluminum, and aluminum complex in a solvent such as alcohol or water.

The zinc alkoxide is not particularly restricted but includes, for example, zinc dimethoxide, zinc diethoxide,
Examples thereof include zinc di-n-propoxide, zinc di-i-propoxide, zinc di-n-butoxide, zinc disec-butoxide, and zinc di-t-butoxide. The zinc chloride is not particularly limited, and may be a hydrate or an anhydride.

The zinc nitrate is not particularly limited, and may be a hydrate or an anhydride. The organic zinc acid is not particularly limited, and examples thereof include zinc acetate, zinc oxalate, zinc benzylate, zinc 2-ethylhexanoate, and the like. The zinc complex is not particularly limited,
Examples include tin diacetylacetone.

The aluminum alkoxide is not particularly restricted but includes, for example, aluminum trimethoxide,
Examples include aluminum triethoxide, aluminum tri-n-propoxide, aluminum tri-i-propoxide, aluminum tri-n-butoxide, aluminum sec-butoxide, and aluminum t-butoxide. The aluminum chloride is not particularly limited, and may be a hydrate or an anhydride.

The aluminum nitrate is not particularly limited, and may be a hydrate or an anhydride. The organic acid aluminum is not particularly limited, for example,
Aluminum laurate and the like can be mentioned. The aluminum complex is not particularly restricted but includes, for example, aluminum triacetylacetone.

The above-mentioned coating solution is optionally used,
A known binder may be added for hydrolysis with an acid or the like or for easy coating. In addition, a seed crystal may be added so that the film is easily crystallized. In that case, however, it is necessary to pay attention to the particle size and the amount of the seed crystal so as not to impair the transmittance of the film. In preparing the coating solution, operations such as stirring, heating, reflux, and cooling are performed as necessary.

The method for applying the coating solution to the glass fiber is not particularly limited, and a known method may be used. For example, you may apply with a brush etc. and may spray. As a simple method, there is a method in which glass fibers are continuously passed through a coating solution.

In the above method for producing a transparent conductive fiber, the coating solution is applied to the surface of the glass fiber as described above, and then processed to form a metal oxide thin film. The above treatments include drying, heat treatment, etc.
To obtain a transparent and conductive metal oxide thin film by converting the metal oxide precursor into a metal oxide, such as a treatment for obtaining a metal oxide precursor coating and subsequent heating and / or light irradiation. And the like.

When the glass fibers used in the above method are applied continuously, long fibers are preferred from the viewpoint of processing efficiency, and if necessary, washing, alkali treatment, etc., so that the coating solution can be easily applied. May be pre-processed.

The drying method is not particularly limited.
A known method may be used. For example, air drying may be used, or heat, wind, hot air, hot wire, or the like may be used as needed.

The heating method is not particularly limited.
Known heating and firing methods may be used, and examples include a method using an oven or a muffle furnace, a direct heating method using a resistance heating element or a far-infrared heater, a heating method using a microwave, or the like.

The light source used for the light irradiation is not particularly limited, and examples thereof include lasers such as carbon dioxide, YAG, and excimer; mercury lamps such as low-pressure mercury lamps and high-pressure mercury lamps; ultraviolet lamps such as metal halide lamps; And the like.

The operations of the heating and the light irradiation may be performed simultaneously or sequentially, or may be performed independently. After the coating solution is applied, light irradiation may be performed without drying.

The above-mentioned heating and light irradiation processes may be carried out in an atmosphere of air; an inert gas atmosphere such as nitrogen or argon; Further, annealing or the like may be performed as necessary.

The conditions of the heating and the light irradiation are appropriately selected depending on the type of the metal oxide and the metal oxide precursor. The temperature applied to the glass fiber is preferably 500 ° C. or less when an oven or the like is used, except for the case where the glass fiber is locally heated such as when irradiating a laser beam.

In order to carry out these treatments continuously, for example, as shown in FIG. 1, the glass fibers are continuously fed, passed through the coating solution, dried with hot air, and heated while irradiating light. Then, a method of obtaining the transparent conductive fiber of the present invention by passing through an annealing furnace in a nitrogen atmosphere, and cooling and winding the same is cited.

According to a third aspect of the present invention (invention 2), a plurality of transparent conductive fibers are brought into electrical contact with the inside and / or the surface of a resin molded product having a total light transmittance of 70% or more. A transparent electromagnetic wave shielding material having a total light transmittance of 60% or more, wherein the transparent conductive fiber is formed by coating the surface of a glass fiber with a metal oxide thin film, The metal oxide thin film is a transparent electromagnetic wave shielding material characterized in that the total light transmittance is 70% or more and the specific resistance is 10 ^-1 Ωcm or less.

The resin molded article used in the present invention 2 is a transparent resin molded article having a total light transmittance of 70% or more. When the total light transmittance is less than 70%, it is difficult to make the total light transmittance of the obtained transparent electromagnetic wave shielding material equal to or more than 60%, so that the above range is limited.

The transparent resin molded article is not particularly limited as long as it has a total light transmittance of 70% or more. For example, a vinyl chloride resin molded article, an acrylic resin molded article,
Polycarbonate-based resin molded articles and the like can be mentioned.

The transparent conductive fiber used in the present invention 2 comprises:
The surface of the glass fiber is coated with a metal oxide thin film, and the metal oxide thin film has a total light transmittance of 70%.
% Or more, and the specific resistance is 10 ^-1 Ωcm or less. When the total light transmittance of the metal oxide thin film is less than 70%, the total light transmittance of the obtained electromagnetic wave shielding material is 60%.
% Or more, it is difficult to set the ratio to not less than the above range.

The specific resistance of the metal oxide thin film is 10 ^-1 Ωc.
When m exceeds m, the electromagnetic wave shielding performance cannot be obtained, so that it is limited to the above range. As the transparent conductive fiber, those described in the section of the description of the transparent conductive fiber of the first aspect of the present invention can be used.

The transparent electromagnetic wave shielding material of the second aspect of the present invention is provided on the inside and / or the surface of the transparent resin molded body so as to electrically contact a plurality of transparent conductive fibers. The inside and / or the surface of the transparent resin molded body may be only the inside of the transparent resin molded body, may be only the surface, or may be both the inside and the surface.

In order to provide the plurality of transparent conductive fibers so as to be in electrical contact with the inside and / or the surface of the transparent resin molded body, the transparent conductive fibers may be arranged in parallel or crossed. May be arranged. If the amount of the transparent conductive fibers provided is too small, a sufficient electromagnetic wave shielding effect cannot be obtained. Further, the transparent conductive fiber may be used as a woven fabric.

The method of providing the plurality of transparent conductive fibers or the woven fabric thereof inside and / or on the surface of the transparent resin molded body is not particularly limited, and the transparent conductive fiber is sandwiched between flat plates of the transparent resin molded body and press-molded. Method: A method of sticking to the surface of the transparent resin molded article with an adhesive or the like; a method of previously setting the transparent conductive woven fabric in a mold and performing molding such as cast molding, injection molding, and multilayer extrusion molding. No.
By integrating the transparent resin molded body and the transparent conductive fiber or its woven fabric in this manner, the strength as a member can be increased.

The total light transmittance of the transparent electromagnetic wave shielding material of the present invention 2 is 60% or more. If the total light transmittance is less than 60%, the amount of transmitted light is small, and the visibility of an image viewed therethrough is not good.

The transparent electromagnetic wave shielding material of the present invention 2 is superior in durability as compared with the case where the above-mentioned transparent conductive fiber is directly provided on the above-mentioned transparent resin molded article, and is electrically conductive even when an external force is applied. Contact is ensured, and electromagnetic wave shielding performance is maintained. In addition, since the transparent conductive fiber is coated with a metal oxide thin film using glass fiber as a base material, the difference in thermal expansion is small and cracks are unlikely to occur, and even if cracks are formed, the surface is like a continuous film. It does not run across, maintaining conductivity when viewed from the entire member.

Since the transparent conductive fiber itself is transparent, the transparency is not impaired even when integrated with the transparent resin molding having a total light transmittance of 70% or more.

When the transparent electromagnetic wave shielding material is used, the conductive glass fiber portion is preferably electrically grounded.

The method for producing the transparent electromagnetic wave shielding material of the present invention 2 is not particularly limited. For example, a transparent conductive fiber is produced by providing a transparent conductive metal oxide thin film on a glass fiber by sputtering or the like. A method in which a plurality of transparent conductive fibers are provided inside and / or on the surface of a transparent resin molded article is exemplified.

According to a fourth aspect of the present invention, there is provided a method for producing the transparent electromagnetic wave shielding material according to the second aspect of the present invention. In producing a transparent conductive fiber, a coating solution is applied to the surface of the glass fiber, This is a method for producing a transparent electromagnetic wave shielding material using a woven fabric of the transparent conductive fiber when forming a metal oxide thin film by treatment and providing a plurality of transparent conductive fibers in electrical contact.

In the above method, in order to produce a transparent conductive fiber, first, a coating solution is applied to the surface of the glass fiber. Thereafter, if necessary, drying, heat treatment, and the like are performed to obtain a metal oxide precursor coating, and further, treatment such as heating and / or light irradiation is performed to obtain a transparent and conductive metal oxide thin film.

In the above method, in order to provide a plurality of transparent conductive fibers so as to be in electrical contact with each other, the transparent conductive fibers are used as a woven fabric. Thus, electrical contact can be ensured, and the density of the plurality of transparent conductive fibers provided inside and / or on the surface of the transparent resin molded body can be controlled by weaving the woven fabric. .

The transparent conductive woven fabric may be prepared by applying a coating solution to glass fiber to produce a transparent conductive fiber and then forming the woven fabric, or by applying the coating solution to a glass fiber woven fabric. A transparent conductive woven fabric may be produced.
In order to carry out these treatments continuously, for example, as shown in FIGS. 1 and 2, while continuously feeding glass fiber or woven fabric, it is passed through a coating solution, dried with hot air,
A method of obtaining the transparent conductive fiber of the present invention by heating while irradiating light, passing through an annealing furnace in a nitrogen atmosphere, cooling, and winding the same is exemplified.

From the viewpoint of processing efficiency, it is better to perform a process of forming a metal oxide thin film on a woven fabric of glass fiber. However, when the gap between the fibers of the woven fabric is narrow, the coating liquid is accumulated. Since the transparency may be deteriorated after the treatment, it is more preferable to form a woven fabric after forming the metal oxide thin film on the glass fiber.

As a method for converting the above glass fibers into a woven fabric, a known method using a loom or the like is used, and examples thereof include plain weave and twill weave. Among them, those which are woven in a mesh shape or a net shape and have a pore ratio of 50% or more, which is a ratio of the area of the gap formed by the fibers to the total area, are preferable.

[0061]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

Example 1 A long fiber of E glass was set in a jig as shown in FIG. 3 and set in a chamber of a sputtering apparatus. ITO while sending glass fiber at a speed of 3 mm / min while rotating
(Indium oxide doped with 5% of tin oxide) as a target, a high frequency of 13.56 MHz is supplied, and sputtering is performed at a pressure of 5 × 10 ⁻³ Torr in the chamber, and a conductive film having an ITO thin film formed on the surface of glass fiber is formed. A fiber was made. The thickness of the ITO thin film, the total light transmittance of the thin film, and the specific resistance were measured by the following methods, and are shown in Table 1.

The obtained conductive fiber was cut into a length of 1 mm to obtain a short fiber. Methyl methacrylate 100
With respect to parts by weight, 0.1 parts by weight of benzoyl peroxide was added, and 15 parts by weight of the conductive fiber was added and mixed. To this was added 0.8 parts by weight of benzoyl peroxide, and the mixture was cast to prepare a plate-shaped resin molded article sample having a thickness of 2 mm. The total light transmittance of this resin molded product sample was measured by the following method, and the results are shown in Table 1.

(Measurement of Film Thickness of Metal Oxide Thin Film) The cross section of the obtained conductive fiber was observed by SEM to measure the film thickness. (Total light transmittance of thin film) A metal oxide thin film having the same thickness as the metal oxide thin film coated on the glass fiber in the example was prepared on a glass plate, and the total light transmittance was determined by the method of ASTM D-1003. Was measured. The total light transmittance of the glass plate, which was measured in advance, was defined as 100%, and the measured value was converted to the total light transmittance of the film. (Specific Resistance of Thin Film) A resistance value was measured by a four-probe method using a sample whose total light transmittance was measured. The resistance was divided by the film cross-sectional area to obtain a specific resistance. (Total light transmittance) The total light transmittance of the resin molded product sample was determined by AS
It was measured by the method of TM D-1003.

Example 2 To 65 parts by weight of isopropyl alcohol, 10 parts by weight of acetylacetone were added and stirred, and 8.0 parts by weight of indium tri-n-butoxide and 0.7 parts by weight of tin tetra-n-butoxide were added. Further, a mixture of 2.5 parts by weight of 0.1N hydrochloric acid and 13.8 parts by weight of isopropyl alcohol was added, and the mixture was stirred at room temperature to obtain a coating solution.

Glass fiber made of E glass having an outer diameter of 0.1 mm was dipped in the coating solution, pulled up, dried in an oven set at 100 ° C. for 30 minutes, and dried in a nitrogen atmosphere for 9 minutes.
Heat to 450 ° C while irradiating with a 0 W low pressure mercury lamp,
Time firing, irradiation with a low-pressure mercury lamp, annealing in a nitrogen atmosphere at 250 ° C for 1 hour, and ITO on the glass fiber surface
A conductive fiber on which a thin film was formed was produced. IT obtained
The thickness, total light transmittance, and specific resistance of the O thin film were measured in the same manner as in Example 1, and the results are shown in Table 1. The conductive fiber obtained in the same manner as in Example 1 was added to the resin to prepare a resin molded product sample. The total light transmittance of the resin molded product sample was measured in the same manner as in Example 1, and the results are shown in Table 1.

Example 3 10 parts by weight of acetylacetone was added to 65 parts by weight of isopropyl alcohol, and the mixture was stirred to obtain tin tetra n-butoxide.
2 parts by weight and 1.5 parts by weight of antimony penta n-butoxide were added. Further, a mixture obtained by mixing 2.3 parts by weight of 0.1N hydrochloric acid with 14.0 parts by weight of isopropyl alcohol was added and stirred at room temperature to obtain a coating solution. The above coating solution was treated in the same manner as in Example 2 to produce a conductive fiber having an ATO thin film formed on the surface of a glass fiber. The thickness, total light transmittance and specific resistance of the obtained ATO thin film were measured in the same manner as in Example 1, and the results are shown in Table 1. In the same manner as in Example 1, the obtained conductive fiber was added to the resin to prepare a resin molded article sample. Table 1 shows the total light transmittance of the resin molded product sample.

Example 4 A glass fiber having a metal oxide film was produced using an apparatus as shown in FIG. A glass fiber having a diameter of 30 μm made of E glass was passed through the coating solution prepared in Example 2, dried in a hot-air drying oven, and irradiated with a carbon dioxide gas laser at an energy density of 0.3 W / mm ² . Winding was performed while cooling, to prepare a conductive fiber having an ITO thin film formed on the surface of a glass fiber. Thickness of the obtained ITO thin film,
The total light transmittance and the specific resistance were measured in the same manner as in Example 1,
The results are shown in Table 1. In the same manner as in Example 1, the obtained conductive fiber was added to the resin to prepare a resin molded article sample. Table 1 shows the total light transmittance of the resin molded product sample.

Example 5 A glass fiber having a metal oxide film was produced using an apparatus as shown in FIG. A glass fiber having a diameter of 30 μm made of E glass is passed through the coating solution prepared in Example 2, dried in a hot-air drying furnace, and heated to 250 ° C. while irradiating with a Xe ₂ excimer lamp. Through
Winding was performed while cooling, to prepare a conductive fiber having an ITO thin film formed on the surface of a glass fiber. The thickness, total light transmittance and specific resistance of the obtained ITO thin film were measured in the same manner as in Example 1, and the results are shown in Table 1. In the same manner as in Example 1, the obtained conductive fiber was added to the resin to prepare a resin molded article sample. Table 1 shows the total light transmittance of the resin molded product sample.

Comparative Example 1 A polyester fiber having a diameter of 45 μm was electrolessly plated with Ni to produce a fiber. The thickness, total light transmittance and specific resistance of the Ni thin film were measured in the same manner as in Example 1, and the results are shown in Table 1. In the same manner as in Example 1, the obtained fiber was added to the resin to prepare a resin molded article sample. Table 1 shows the total light transmittance of the resin molded product sample.

Comparative Example 2 Glass fibers were produced from soda-lime glass in which an alkali component was added to glass. The specific resistance of the glass itself is 2.0
× 10 ⁸ Ωcm. In the same manner as in Example 1, the obtained glass fiber was added to the resin to prepare a resin molded product sample. Table 1 shows the total light transmittance of the resin molded product sample.

[0072]

[Table 1]

Example 6 A glass fiber made of E glass having an outer diameter of 0.1 mm and a density of 3 was used.
In the same manner as in Example 1, an ITO thin film was formed on a glass cloth plain woven into 0 pieces / inch (vertically and horizontally).
Å was provided. The obtained conductive woven fabric is 2 m thick.
m, transparent vinyl chloride, 160 ° C, 100kg
/ Cm ² so as to prevent air bubbles from entering. The electromagnetic shielding performance of the obtained sample was measured by the following method,
The total light transmittance was measured in the same manner as in Example 1, and the results are shown in Table 2.

(Electromagnetic Wave Shielding Performance) The sample was electrically grounded and fixed in a shield box, and the electromagnetic wave (electric field) shielding effect of 100 MHz and 1 GHz was measured by the Advantest method.

Example 7 A glass fiber made of E glass having an outer diameter of 0.1 mm and a density of 3 was used.
In the same manner as in Example 2, an ITO thin film was coated on a glass cloth plain-woven at 0 pieces / inch (length and width) to prepare a conductive woven fabric. The obtained conductive woven fabric is sandwiched between transparent vinyl chloride having a thickness of 2 mm, and is heated at 160 ° C. and 100 kg / c.
It was pressed so that air bubbles did not enter at m ² . Table 2 shows the electromagnetic wave shielding performance and the total light transmittance of the obtained samples.

Example 8 A glass fiber made of E glass having an outer diameter of 0.1 mm and a density of 3 was used.
In the same manner as in Example 3, an ATO thin film was coated on a glass cloth plain-woven at 0 pieces / inch (length and width) to prepare a conductive woven fabric. The obtained conductive woven fabric is sandwiched between acrylic resin having a thickness of 2 mm and a photosensitive resin containing a liquid acrylic acid oligomer as a main component, lightly pressed so as not to cause air bubbles, and 50 mm with a high-pressure mercury lamp of 160 W / cm.
UV light was irradiated from the distance of 3 minutes. Table 2 shows the electromagnetic wave shielding performance and the total light transmittance of the obtained samples.

Example 9 The conductive fibers obtained in Example 4 were treated at a density of 30 fibers / inc.
h (vertical and horizontal) to prepare a conductive woven fabric. The obtained conductive woven fabric was sandwiched between acrylic plates in the same manner as in Example 8 to produce a sample. Table 2 shows the electromagnetic wave shielding performance and the total light transmittance of the obtained samples.

Example 10 The conductive fibers obtained in Example 5 were subjected to a density of 30 fibers / inc.
h (vertical and horizontal) to prepare a conductive woven fabric. The obtained conductive woven fabric was stuck on an acrylic plate with an acrylic adhesive to prepare a sample. Table 2 shows the electromagnetic wave shielding performance and the total light transmittance of the obtained samples.

Comparative Example 3 A woven cloth having a metal content of 13.3% by weight and 135 mesh was prepared from the conductive fibers used in Comparative Example 1, and was sandwiched between vinyl chloride plates and pressed in the same manner as in Example 6. Table 2 shows the electromagnetic wave shielding performance and the total light transmittance of the obtained samples.

Comparative Example 4 An ITO thin film 500Å was directly formed on a flat plate made of a polycarbonate resin by sputtering. Observation of the surface with a microscope revealed cracks. Table 2 shows the electromagnetic wave shielding performance and the total light transmittance of the obtained samples.

[0081]

[Table 2]

[0082]

Since the transparent conductive fiber of the present invention has the above-mentioned structure, it is used as a filler for a transparent resin, and impairs the transparency of films, sheets, plates, various molded articles, etc. made of the transparent resin. It is possible to provide conductivity without causing any problem, and to provide functions such as prevention of dust adhesion, prevention of electrostatic interference, and shielding of electromagnetic waves. Furthermore, if the direction of the fiber can be oriented in one direction, anisotropic conductivity can be imparted. Further, since the method for producing a transparent conductive fiber of the first aspect of the present invention described in claim 2 has the above-described configuration, the transparent conductive fiber of the first aspect of the present invention can be favorably produced. Invention 2
Since the transparent electromagnetic wave shielding material has the above-described configuration, the transparent resin molded body and the plurality of transparent conductive fibers are integrated. Since both are made of a transparent material, they have excellent transparency and a total light transmittance of 60% or more. Furthermore, since the metal oxide thin film has a specific resistance of 10 ^-1 Ωcm or less, it is a member that can efficiently block electromagnetic waves. In addition, since the method for manufacturing a transparent electromagnetic wave shielding material according to the second aspect of the present invention has the above-described configuration, the transparent electromagnetic wave shielding material according to the second aspect of the present invention can be favorably manufactured.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating an example of a production process of a transparent conductive fiber of the present invention.

FIG. 2 is a diagram showing another example of the process for producing the transparent conductive fiber of the present invention.

FIG. 3 is a view showing a process of manufacturing a transparent conductive fiber of Example 1.

FIG. 4 is a view showing a process for producing a transparent conductive fiber of Example 4.

FIG. 5 is a view showing a process for producing a transparent conductive fiber of Example 5.

Claims (4)

[Claims] 1. A transparent conductive fiber obtained by coating the surface of a glass fiber with a metal oxide thin film, wherein the metal oxide thin film has a total light transmittance of 70% or more and a specific resistance of 1%.
A transparent conductive fiber having a density of 0 ^-1 Ωcm or less. 2. The method for producing a transparent conductive fiber according to claim 1, wherein a solution of a metal oxide precursor is applied to the surface of the glass fiber, and the solution is thereafter processed to form a metal oxide thin film. A method for producing a transparent conductive fiber. 3. A plurality of transparent conductive fibers are provided inside and / or on a surface of a resin molded product having a total light transmittance of 70% or more so as to be in electrical contact with each other.
0% or more of a transparent electromagnetic wave shielding material, wherein the transparent conductive fiber is formed by coating a surface of a glass fiber with a metal oxide thin film, and the metal oxide thin film has a total light transmission property. A transparent electromagnetic wave shielding material having a ratio of 70% or more and a specific resistance of 10 ^-1 Ωcm or less. 4. The method for producing a transparent electromagnetic wave shielding material according to claim 3, wherein a solution of a metal oxide precursor is applied to a surface of the glass fiber when producing the transparent conductive fiber. Forming a metal oxide thin film by the treatment, and providing a plurality of transparent conductive fibers so as to be in electrical contact with each other, the transparent electromagnetic wave shielding material characterized by using a woven fabric of the transparent conductive fibers Production method.