JP2003025470A - Conductive mesh fabric and its production method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a conductive mesh fabric applicable to a durable electronic display front plate with the migration of a conductive metal controlled in a laminate in which a glass or transparent resin plate and a mesh fabric of long fibers having a conductive metal layer on the periphery are bonded together by a carboxyl group-containing adhesive resin. SOLUTION: In the conductive mesh fabric, in the laminate in which the glass or transparent resin plate and the mesh fabric of the long fibers having the conductive metal layer having a metal oxide surface film having a finely uneven surface on the periphery are bonded together by the carboxyl group- containing adhesive resin, a migration preventive treatment part and/or a rust preventive coat are formed on the surface of the conductive metal layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic display device which is laminated with a transparent resin plate and shields electromagnetic waves emitted from an electronic display device used as a front plate of a television, a computer, a plasma display or the like. The present invention relates to a conductive mesh woven fabric that imparts an antiglare property to a screen, reduces discoloration due to migration of a metal such as copper, and prevents deterioration of a front plate for a long period of time, and a manufacturing method thereof.

[0002]

2. Description of the Related Art As a visible-light-transmitting electromagnetic wave shielding transparent plate, a method of disposing a transparent conductive film such as an ITO film described in JP-A-6-194641, JP-B-5-6360.
As described in JP-A-10-163673, a method of using a conductive mesh in which a metal is added to a mesh fabric composed of a monofilament made of a synthetic polymer, and as described in JP-A-10-163673, conductivity is obtained by using photofabrication. There is a method of regularly arranging the thin wires on the film. However, both methods are conductive (electromagnetic wave shielding)
This is a method that places importance on, and it cannot be said that it is still at a sufficient level in terms of antiglare property. That is, when these screens or films are used as the front plate of the display device, it is difficult to see an image due to specular reflection (mirror reflection) from inside and outside of the front plate, resulting in defects such as lack of contrast. On the other hand, as an antiglare filter, it is disclosed in JP-A-63-2056.
Japanese Unexamined Patent Publication No. 88 discloses a method of imparting irregularities to the surface of a filter to diffuse light from inside and outside the filter to improve antiglare property and contrast property. However, the filter itself has no electrical conductivity (electromagnetic wave shielding property) and needs to be used in combination with an ITO film or the like, resulting in high technical difficulty and high cost. In order to solve the above-mentioned problems, in Japanese Utility Model Publication No. 5-8619, the fiber surface of a fabric having a light transmittance of 20 to 80% is coated with a metal coating, and the surface layer of the metal coating becomes a black layer by an oxidation reaction. The formed conductive shielding screen is introduced. By this method, it is possible to obtain a conductive shielding screen having a fine uneven matte blackened surface on the surface of the metal coating. When this conductive shielding screen is used as an electromagnetic wave shielding light transmitting window material (front plate) of a display device, as described in JP-A No. 11-74683, the conductivity is provided between two transparent substrates. It is used by joining it with a transparent adhesive resin with a mesh interposed. However, if it is used for a long period of time, the front plate may be discolored. The reason for this is presumed to be that metal migration occurs at the interface between the carboxyl-containing resin such as ethylene-vinyl acetate copolymer used as the transparent adhesive resin and the metal.

[0003]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems, and a transparent adhesive resin containing a carboxyl group containing a conductive mesh woven fabric whose surface is coated with a metal film by electroless plating and a resin plate. In a laminate used as a front plate for electronic equipment display, which is laminated and adhered using, it has excellent electromagnetic wave shielding effect, antiglare property, surface conductivity, and excellent effect of preventing discoloration when used as a front plate. Another object of the present invention is to provide a conductive mesh fabric.

[0004]

The above-mentioned various objects of the present invention have been solved by the following means. (1) A glass or transparent resin plate and a mesh woven fabric made of long fibers with a conductive metal layer having a metal oxide film on the surface of which fine irregularities are provided on the outer periphery are bonded with a carboxyl group-containing adhesive resin. In the laminated body
A conductive mesh fabric comprising a conductive metal layer surface on which a migration preventing treatment portion and / or a rust preventive coating is formed. (2) The conductive mesh woven fabric according to (1), wherein the ΔE value after the dry heat and wet heat durability test is less than 5 at the interface between the conductive metal layer and the carboxyl group-containing adhesive resin. (3) The conductive mesh woven fabric according to (1) or (2), wherein the fine irregularities have a depth of 0.01 to 0.1 μm. (4) Using a carboxyl group-containing adhesive resin, a mesh fabric composed of glass or a transparent resin plate and long fibers provided with a conductive metal layer having a metal oxide film having a fine uneven surface on the outer periphery is used. A method for producing a conductive mesh woven fabric, which comprises applying a migration preventing treatment agent and / or a rust preventive agent to a conductive metal layer in a laminated body formed by adhesion. (5) The method for producing a conductive mesh woven fabric according to (4), wherein the conductive metal layer having fine irregularities is formed by oxidizing copper.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. The conductive mesh fabric of the present invention is a mesh fabric having a yarn density of 50 to 300 yarns / inch, which is manufactured by using long-fiber yarns made of synthetic fibers such as polyester and polyamide or natural fibers such as silk. After the pretreatment such as scouring, heat setting and conditioning of the mesh fabric,
After forming a metal coating such as copper on the mesh fabric by an electroless plating method, the metal coating is blackened with an oxidizing agent, and then a migration preventing treatment agent and / or a rust preventive agent is added to form a metal coating. The present invention relates to a conductive mesh woven fabric characterized by performing a migration prevention treatment and a method for producing the same.

The material of the mesh fabric in the present invention is polyester fiber such as polyethylene terephthalate,
Synthetic fibers such as polyamide fibers such as 6 nylon and 66 nylon, or long fibers such as natural fibers such as silk are preferably used, and polyester fibers are particularly preferable in terms of processability and durability. Further, in order to suppress the generation of fluff and the like, it is preferable to use a yarn made of long fibers, and the form may be a monofilament yarn or a multifilament yarn, and is not particularly limited. The yarn density is preferably 50 to 300 yarns / inch. If it is larger than 300 lines / inch, the screen becomes dark when it is installed in front of the display due to its low light transmission.
On the other hand, when it is less than 50 lines / inch, the light transmittance is high and the screen is bright, but a sufficient electromagnetic wave shielding effect cannot be obtained. The visible light transmittance is preferably 50 to 75%. If the visible light transmittance is less than 50%, the display screen will be dark and difficult to recognize. If the visible light transmittance is more than 75%, the thread to be used will be thin and the mesh fabric opening must be large. If not, the weaving and workability may be deteriorated.

The metal used is not particularly limited as long as it has conductivity and electromagnetic wave shielding properties, and gold, silver, copper, nickel, chromium, etc. can be used, but the cost, Copper is preferred from the viewpoints of workability and shieldability. The metal coating is preferably formed by electroless plating or a combination of electroless plating and electroplating in order to form a coating having a uniform thickness. The thickness of the metal coating formed on the surface of the base material is 0.1 to 1 μm.
It is preferably in the range of. Metal coating thickness is 0.1μ
If it is less than m, the surface conductivity is insufficient and a sufficient electromagnetic wave shielding effect cannot be obtained. If it is thicker than 1 μm, the original flexibility of the mesh fabric will be impaired and it will become rigid.
The obtained electromagnetic wave shielding performance is not particularly improved, resulting in an increase in cost. After forming the metal coating on the surface of the mesh fabric, the metal oxide coating is formed by the oxidation treatment. Examples of the oxidizing agent used in the oxidation treatment include chlorate, perchlorate, hypochlorite, and chlorite. Further, it is preferable to add a hydroxide salt in order to prevent decomposition of the oxidant or to stabilize the oxidation performance. The oxidation treatment condition is, for example, 70 to 9 when copper is used for the metal coating.
A copper oxide film can be obtained by immersion treatment at 0 ° C. for 2 to 10 minutes. The copper oxide obtained by the oxidation treatment is in a needle-like crystal state, so that irregularities (etching) are formed on the surface of the copper coating. The degree of etching depth is 0.01 to 0.1
It is preferably μm. If it is less than 0.01 μm, sufficient antiglare property cannot be obtained, and if it is more than 0.1 μm, the electromagnetic wave shielding effect and surface conduction performance are deteriorated due to deterioration of the copper coating. It goes without saying that the etching depth can be appropriately adjusted depending on the oxidant concentration of the processing liquid, the processing temperature, the processing time, and the like.

After the metal oxide film is formed by the oxidation treatment, the migration prevention treatment is performed. Examples of the anti-migration agent used in the present invention include anti-migration agents that prevent migration of metal ions, and rust preventive agents that combine with metal ions to form an anti-corrosion film. As the anti-migration agent, oxalic acid, malonic acid, succinic acid, glutaric acid, dicarboxylic acids such as adipic acid, ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), hydroxyethylethylenediaminetetraacetic acid (HEDTA), Diethylenetriamine pentaacetic acid (DTPA), Triethylenetetramine hexaacetic acid (TTH
Examples thereof include aminocarboxylic acid salts such as A), hydroxyethyliminodiacetic acid (HIDA), and dihydroxyethylglycine (DHEG), but they are not particularly limited and may be used alone or in combination. Examples of the rust preventive agent include benzotriazole derivatives such as benzotriazole or benzotriazole monoethanolamine salt, benzotriazole diethylamine salt, and rust preventive agents having a triazine thiol compound as a main component, but are not particularly limited and may be used alone or as a mixture. It may be used as a liquid. Generally, the treatment agent concentration is 0.
The desired black conductive coating can be obtained by dipping treatment for 1 to 50%, treatment temperature 20 to 90 ° C., and 0.5 to 10 minutes. When the anti-migration treatment and the anti-rust film forming treatment are used together, the anti-migration effect is further improved. By carrying out such migration prevention treatment, metal migration can be prevented or greatly reduced, and even when used as a front plate, there is little discoloration, and excellent performance such as antiglare property and electromagnetic wave shielding property. Can be maintained for a long period of time.

The carboxyl group-containing adhesive resin is preferably a transparent and elastic one, for example, one which is usually used as an adhesive for laminated glass, and specifically, ethylene-vinyl acetate copolymer, ethylene- Methyl acrylate copolymer, ethylene-methacrylic acid copolymer, ethylene-ethyl methacrylate copolymer, ethylene-methyl methacrylate copolymer, metal ion crosslinked ethylene-
Methacrylic acid copolymer, partially saponified ethylene-vinyl acetate copolymer, carboxyl ethylene-vinyl acetate copolymer, ethylene-methacrylic-maleic anhydride copolymer, ethylene-vinyl acetate-methacrylate copolymer, etc. Examples thereof include ethylene-based copolymers. In addition, polyvinyl butyral resin, epoxy resin, acrylic resin, phenol resin, silicone resin, polyester resin, urethane resin, etc. can be used, but ethylene-vinyl acetate is the most balanced and easy to use in terms of performance. It is a copolymer.

[00010]

EXAMPLES Examples of the conductive mesh fabric of the present invention will be further described below.

[Evaluation method] Durability test (dry heat test: sample at 80 ° C for 1
The sample was allowed to stand for 000 hours and subjected to a moist heat test: the sample was allowed to stand at 60 ° C. and 95% RH for 1000 hours), and the following performances of the samples before and after the durability test were investigated. (1) Surface irregularities Surface irregularities were measured using a scanning probe microscope system (SPI3800N manufactured by Seiko Instruments Inc.). The unit is μm. (2) The reflectance (%) of the sample surface at 400 to 700 nm was measured using a surface reflectance spectrophotometer (Macbeth Color Eye CE3100 manufactured by Gredagu Macbeth Co., Ltd.), and the average value thereof was calculated. (3) Visible Light Transmittance Spectrophotometer (Macbeth Color Eye CE3100 manufactured by Gredagu Macbeth Co., Ltd.) Transmittance (%) at 400 to 700 nm with and without a sample installed
Was measured and the average value was calculated. (4) Color change measurement A sample coated with an ethylene-vinyl acetate copolymer was subjected to a durability test using a laminated body sandwiched in a pouch film having a polyester film as a base material, before and after the durability test. The laminate was evaluated. The degree of discoloration is L ^* a ^*
The ΔE value represented by the following formula 1 in the b ^* color system (JIS Z 8729) was calculated.

[Formula 1] Here, L ^* ₀ , a ^* ₀ , and b ^* ₀ are L ^* a ^* b ^* before the durability test ^.
It is a value. (5) The blackness measurement sample was measured using a spectrophotometer (Macbeth Color Eye CE3100 manufactured by Gredagu Macbeth Co., Ltd.) to obtain L ^* a ^*.
b ^* Expressed in color system. Empirically, L ^* <20, | a ^* | <
5, if | b ^* | <5, the object is regarded as black. (6) Conductive mesh fabric surface conductivity Mitsubishi Chemical Co., Ltd. resistance measuring instrument Loresta EP (MCP
-T360) was used to measure the conductivity according to the four-point probe method JIS K7194. (7) The electromagnetic wave shielding effect measurement method uses a measuring cell devised by the Ikoma Radio Measuring Station of Kansai Electronics Industry Promotion Center, and uses a spectrum analyzer HP8591EM with tracking generator manufactured by Hewlett-Packard Co. to oscillate 10 MHz to 1 GHz at the measuring cell receiving section. The measurement sample was received and then weighed with a spectrum analyzer.

[0011]

Example 1 A polyester monofilament having a fineness of 13 dtex was woven at a yarn density of 135 filaments / inch,
Using this woven fabric, 0.3 g of palladium chloride /
L, stannous chloride 30 g / L, 36% hydrochloric acid 300 ml / L
It was immersed in an aqueous solution of 40 ° C. containing water for 2 minutes and then washed with water. Then, it was immersed in hydrofluoric acid having an acid concentration of 0.1 N at 30 ° C. for 5 minutes and washed with water. Next, it was immersed in an electroless copper plating solution consisting of 7.5 g / L of copper sulfate, 30 ml / L of 37% formalin, and 85 g / L of Rochelle salt at 30 ° C. for 5 minutes and then washed with water. As a result, a copper coating having a thickness of about 0.5 μm was formed on the polyester filament. After forming the copper film, use sodium chlorite 10% sodium hydroxide 3% solution for oxidation treatment 8
After dipping at 0 ° C. for 10 minutes to form a black copper oxide film having a thickness of about 0.1 μm, it was treated with a 2% oxalic acid solution at room temperature for 2 minutes to obtain a target conductive mesh fabric. The evaluation results are shown in Table 1.

[0012]

[Example 2] Polyester monofilaments having a fineness of 13 dtex were woven at a yarn density of 135 filaments / inch, and this woven fabric was subsequently used as an electroless plating method in an amount of 0.3 g / L of palladium chloride and 30 g / L of stannous chloride. , 36%
It was immersed in a 40 ° C. aqueous solution containing 300 ml / L of hydrochloric acid for 2 minutes and then washed with water. Then, it was immersed in hydrofluoric acid having an acid concentration of 0.1 N at 30 ° C. for 5 minutes and washed with water. Next, 7.5 g of copper sulfate /
L, 37% formalin 30 ml / L, Rochelle salt 85
It was immersed in an electroless copper plating solution of g / L at 30 ° C. for 5 minutes and then washed with water. As a result, a copper coating having a thickness of about 0.5 μm was formed on the polyester filament. After forming the copper film, a 10% sodium chlorite 3% sodium hydroxide solution was used as an oxidation treatment for immersion treatment at 80 ° C. for 10 minutes to form a black copper oxide film of about 0.1 μm, and then benzotriazole monoethanol. It was treated with a 2% solution of an amine salt solution at room temperature for 2 minutes to obtain a target conductive mesh fabric. The results of conducting the same evaluations as in Example 1 on the obtained conductive mesh fabric are shown in Table 1.

[0013]

[Example 3] Polyester monofilaments having a fineness of 13 dtex were woven at a yarn density of 135 filaments / inch, and this woven fabric was continuously used as an electroless plating method to obtain 0.3 g / L of palladium chloride and 30 g / L of stannous chloride. , 36%
It was immersed in a 40 ° C. aqueous solution containing 300 ml / L of hydrochloric acid for 2 minutes and then washed with water. Then, it was immersed in hydrofluoric acid having an acid concentration of 0.1 N at 30 ° C. for 5 minutes and washed with water. Next, 7.5 g of copper sulfate /
L, 37% formalin 30 ml / L, Rochelle salt 85
It was immersed in an electroless copper plating solution of g / L at 30 ° C. for 5 minutes and then washed with water. As a result, a copper coating having a thickness of about 0.5 μm was formed on the polyester filament. After forming the copper film, as a oxidization treatment, a 10% sodium chlorite 10% sodium hydroxide 3% solution was used for dipping treatment at 80 ° C. for about 0.
After forming 1 μm black copper oxide film, oxalic acid 2%
After being treated with the solution at room temperature for 2 minutes, it was further treated with a 2% solution of benzotriazole monoethanolamine salt solution at room temperature for 2 minutes to obtain a target conductive mesh fabric. The results of conducting the same evaluations as in Example 1 on the obtained conductive mesh fabric are shown in Table 1.

[0014]

[Comparative Example 1] Polyester monofilaments having a fineness of 13 dtex were woven at a yarn density of 135 filaments / inch, and this woven fabric was subsequently used as an electroless plating method in which palladium chloride was 0.3 g / L and stannous chloride was 30 g / L. , 36%
It was immersed in a 40 ° C. aqueous solution containing 300 ml / L of hydrochloric acid for 2 minutes and then washed with water. Then, it was immersed in hydrofluoric acid having an acid concentration of 0.1 N at 30 ° C. for 5 minutes and washed with water. Next, 7.5 g of copper sulfate /
L, 37% formalin 30 ml / L, Rochelle salt 85
It was immersed in an electroless copper plating solution of g / L at 30 ° C. for 5 minutes and then washed with water. As a result, a copper coating having a thickness of about 0.5 μm was formed on the polyester filament. After the copper coating was formed, a 10% sodium chlorite 3% sodium hydroxide solution was used as an oxidation treatment, and a dipping treatment was performed at 80 ° C. for 10 minutes to form a black copper oxide coating having a thickness of about 0.1 μm. The evaluation results are shown in Table 1.

[0015]

Comparative Example 2 Polyester filaments having a fineness of 13 dtex were woven at a yarn density of 135 filaments / inch, and then a copper coating having a thickness of about 0.5 μm was formed by an electroless plating method. After forming the copper coating, a black nickel coating having a thickness of about 0.5 μm was further formed by electroplating. The evaluation results are shown in Table 1.

[0016]

[Table 1]

[0017]

The conductive mesh fabric obtained by the method of the present invention exhibits excellent antiglare property, corrosion resistance, surface conductivity, and electromagnetic wave shielding property, and is easily grounded when used as a front plate for electronic display devices. , You can easily take electromagnetic wave shield measures. Further, the obtained oxide film is black in itself, and it is not necessary to laminate a black film in the post-processing unlike the conventional case, so that the filament diameter is not increased in the processing and the visible light transmittance is decreased. Never. In addition, there is little discoloration due to metal migration to the adhesive resin used in manufacturing the front plate, and it is possible to prevent image deterioration for a long period of time.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4F100 AA17B AB17B AG00A AK01A                       AK12 BA02 DD07B DG01B                       DG12B EJ12B GB90 JG01B                       JN01A YY00B                 4L031 AA01 AA18 AA20 AB32 BA04                       CA02 CB12 DA15                 4L033 AA02 AA03 AA07 AA08 AB05                       AC06 AC15 BA18                 5E321 AA21 BB23 BB25 BB41 CC16                       GG05 GH01 GH10

Claims (5)

[Claims] 1. A mesh fabric comprising a glass or transparent resin plate and a long fiber provided with a conductive metal layer having a metal oxide film on the surface of which fine irregularities are provided on the outer periphery by a carboxyl group-containing adhesive resin. A conductive mesh woven fabric comprising a laminated body formed by adhering and having a migration preventing treatment portion and / or a rust preventive coating formed on the surface of the conductive metal layer. 2. The conductive mesh according to claim 1, wherein the ΔE value after the dry heat and wet heat durability test is less than 5 at the interface between the conductive metal layer and the carboxyl group-containing adhesive resin. fabric. 3. The conductive mesh woven fabric according to claim 1, wherein the fine concavo-convex shape has a depth of 0.01 to 0.1 μm. 4. A mesh fabric made of glass or transparent resin plate and long fibers provided on the outer periphery with a conductive metal layer having a metal oxide film on the surface of which fine irregularities are formed, and a carboxyl group-containing adhesive resin. In a laminate formed by using and adhering to the conductive metal layer, a migration preventing treatment agent and / or
Alternatively, a method for producing a conductive mesh woven fabric, which comprises adding a rust preventive agent. 5. The method for producing a conductive mesh woven fabric according to claim 4, wherein the conductive metal layer having fine irregularities is formed by oxidizing copper.