JPH07153317A - Antistatic transparent conductive plate - Google Patents

Abstract

PURPOSE:To provide an antistatic transparent conductive plate whose transparent conductive plate is not seen distorted. CONSTITUTION:An antistatic transparent conductive plate 3 is a plate consisting of a transparent conductive plate 1 and an antistatic transparent hardened coating 2, wherein the conductive plate is prepared by putting a conductive mesh in a base part made of a transparent electrically insulating material and the coating 2 is formed by applying an ultraviolet ray curable conductive paint to the transparent conductive plate and hardening the paint, wherein the conductive mesh is prepared by combining a plurality of conductive wires and a plurality of electrically insulating wires which do not cross mutually to form a mesh. The ultraviolet ray curable conductive paint consists of mainly tin oxide containing antimony oxide, a conductive powder with 0.01-0.4mum particle diameter, a paint binder mainly consisting of (meth)acrylate compound having two or more acryloyl groups or methacryloyl groups in one molecule at 10-100 parts by weight to 100 parts by weight of the conductive powder, 5-50 parts by weight of a dispersant of acetal resin having a function to make the viscosity of the paint suitable to apply the paint and to improve the smoothness of the coating, 0.1-10 parts by weight of photopolymerization starter, and 100-1000 parts by weight of an organic solvent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent conductive plate, and more particularly to improvement of an antistatic transparent conductive plate having excellent antistatic property, transparency and scratch resistance.

[0002]

2. Description of the Related Art As a transparent conductive plate of this type, one having a structure described in Japanese Patent Application Laid-Open No. 63-174216 related to the invention of the present applicant is known. That is, for example, as shown in FIGS. 2 (A) to 2 (C), this transparent conductive plate forms a conductive mesh c by incorporating a plurality of conductive wires a and electrically insulating wires b that do not intersect each other in a net shape. The conductive mesh c is embedded in a plate-shaped base portion made of a transparent electrically insulating material (resin material, glass, etc.).

By the way, when a resin material is applied as the transparent electric insulating material, there are problems that it is easily scratched and dust is easily attached due to static electricity.

Therefore, there is a demand for a transparent conductive plate which maintains transparency and has scratch resistance and antistatic properties.
As a means for imparting the antistatic property, conventionally, a method of coating the surface of the target member with a coating material containing carbon powder or metal powder, or kneading these powders into a resin to mold the target member has been adopted. Has been.

However, in these conventional methods, the coating film and the molded product itself are colored, so that they are opaque, the contents cannot be seen through, and they cannot be used in applications requiring transparency. .

In order to solve such a problem, Japanese Unexamined Patent Publication No.
Japanese Patent Publication No. 7-85866 discloses a paint in which conductive fine powder containing tin oxide as a main component is contained in a paint binder. This paint can form a coating film that is transparent and has an antistatic function, but since the coating binder is composed of a thermoplastic resin, the resulting coating film generally exhibits scratch resistance and solvent resistance. There was a drawback I couldn't get.

On the other hand, in JP-A-60-60166, in order to improve the above-mentioned scratch resistance and solvent resistance, conductive fine powder containing tin oxide as a main component is contained in a photocurable coating binder. A coating composition that is cured by ultraviolet rays or visible light has been proposed.

[0008]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
The paint described in Japanese Patent No. -60166 has a problem that the viscosity of the paint is low, and the coating film can be formed only by a method such as a spray method or a dipping method, so that the utilization efficiency of the expensive paint is low, and Due to the low smoothness of the formed coating film, there is a problem that the object looks distorted when viewed through the transparent conductive plate on which the coating film is formed.

The present invention has been made by paying attention to such problems, and an object thereof is to provide an antistatic transparent transparent conductive plate in which the smoothness of the antistatic transparent cured coating film is improved. Especially.

[0010]

That is, the invention according to claim 1 is a substrate in which a conductive mesh formed by incorporating a plurality of conductive wires and electric insulating wires that do not intersect each other in a net shape is made of a transparent electric insulating material. Assuming an antistatic transparent conductive plate provided with a transparent conductive plate disposed in a portion, and an antistatic transparent cured coating film formed by curing an ultraviolet curable conductive coating material applied on the transparent conductive plate. The ultraviolet-curable conductive coating material is a conductive powder containing tin oxide containing antimony oxide as a main component and having a particle size of 0.01 to 0.4 μm, and 100 parts by weight of the conductive powder. At least 2 in
A coating binder containing as a main component a (meth) acrylate compound having one or more acryloyl groups or methacryloyl groups: 10 to 100 parts by weight, a dispersant consisting of an acetal resin: 5 to 50 parts by weight, and a photopolymerization initiator: 0 .1
10 to 10 parts by weight and an organic solvent: 100 to 1000 parts by weight are included.

In such a technical means, the antistatic transparent conductive plate is prepared by first coating the surface of a transparent conductive plate prepared by a conventional method with the ultraviolet curable conductive coating material of the present invention and then drying it. After that, it can be prepared by irradiating ultraviolet rays to form an antistatic transparent cured coating film. At this time, the film thickness of the antistatic transparent cured coating film is preferably set to 0.5 μm to 3 μm, more preferably 1 μm to 2 μm. If the coating film is thinner than this, antistatic properties and scratch resistance are lost, and if it is thicker, transparency is lost. For ultraviolet irradiation, a medium pressure mercury lamp, a high pressure mercury lamp, a metal halide lamp or the like that generates a large amount of ultraviolet rays is used.
The irradiation dose depends on the type, but it is usually 1000 mJ / cm ²
By the above irradiation, the ultraviolet curable conductive coating material is cured. Further, as a method for applying the ultraviolet curable conductive coating material according to the present invention, a spray method or a dipping method can be applied, but it is preferable to apply a means such as a bar coating method, a doctor blade method or a roll coating method. This is because it is superior in the use efficiency of the paint and the smoothness of the coating film as compared with the spray method or the dipping method. The surface of the obtained coating film may be surface-polished by buffing if necessary. Buffing improves the transparency of the coating film and makes it possible to manufacture a product having an excellent appearance.

Next, the antistatic transparent conductive plate according to this technical means has a conductive powder containing tin oxide as a main component and at least two or more acryloyl groups or methacryloyl groups in the molecule (meth). It is premised to apply a coating binder containing an acrylate compound as a main component, a dispersant composed of an acetal resin, a photopolymerization initiator, and an ultraviolet curable conductive coating material containing a certain proportion of an organic solvent. . The conductive powder contains tin oxide as a main component and contains 0.1-20 antimony.
A tin oxide containing by weight is preferably used. If the particle size of such a conductive powder is too large, visible light is scattered and the transparency of the obtained coating film is reduced, so the particle size is limited to 0.4 μm or less.

Further, it has at least two or more acryloyl groups or methacryloyl groups in the molecule (meth).
Examples of the acrylate compound include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, nonaethylene glycol di (meth).
Acrylate, polyethylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate, tetrapropylene ethylene glycol di (meth) acrylate, nonapropylene ethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, 2,2 -Bis [4- (acryloxydiethoxy) phenyl] propane, 2,2-bis [4- (methacryloxydiethoxy) phenyl] propane, 3-phenoxy-2-propanoyl acrylate,
Bifunctional (meth) acrylates such as 1,6-bis (3-acryloxy-2-hydroxypropyl) -hexyl ether, or pentaerythritol tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, glycerol tri (meth) acrylate Acrylate, trifunctional (meth) acrylate such as tris- (2-hydroxyethyl) -isocyanuric acid ester (meth) acrylate, other pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa ( Examples thereof include tetra- or higher functional (meth) acrylates such as (meth) acrylate. Scratch resistance is imparted to a coating film formed by highly crosslinking this component.

These acrylate compounds are preferably added in an amount of 10 to 100 parts by weight, more preferably 20 to 60 parts by weight, based on 100 parts by weight of the conductive powder. If the amount added is less than 10 parts by weight,
If the crosslink density becomes low, the abrasion resistance and the solvent resistance of the coating film cannot be obtained. On the contrary, if it exceeds 100 parts by weight, the content of the conductive powder becomes small and the conductivity is deteriorated. .

Further, in the above ultraviolet curable conductive coating material, an acetal resin is added as a dispersant in order to improve the dispersibility of the conductive powder. Such an acetal resin is obtained by subjecting polyvinyl alcohol to condensation reaction with an aldehyde to form an acetal. For this acetalization, known methods such as a precipitation method using an aqueous medium in the presence of an acid catalyst and a dissolution method using a solvent such as alcohol are adopted. In addition, using polyvinyl acetate resin as a raw material,
It is also possible to carry out saponification and acetalization in parallel to obtain a polyvinyl acetal resin. As this polyvinyl alcohol, one having an average degree of polymerization of 200 or more is used. If the average degree of polymerization is less than 200, it is difficult to synthesize polyvinyl alcohol, and the viscosity of the solution becomes low,
Not suitable for this purpose. Examples of the aldehyde condensed with polyvinyl alcohol include formaldehyde, acetaldehyde, propionaldehyde, butyraldehyde, amyl aldehyde, hexyl aldehyde, heptyl aldehyde, octyl aldehyde, 2-ethylhexyl aldehyde, decyl aldehyde and cyclohexyl aldehyde. These aldehydes may be used alone or in combination for acetalization. Further, in addition to the acetal portion, an acetyl group may be contained in a proportion of 10% or less. By adding an acetal resin having such a hydroxyl group as a dispersant,
It is possible to give a suitable viscosity suitable for coating to the ultraviolet-curable conductive paint, and the resulting coating film has excellent transparency while maintaining conductivity. If the amount of the acetal resin added is too small, the dispersion effect is lost, the transparency of the coating film is reduced, the thickening effect cannot be exhibited, and the coating property is inferior. Further, if the addition amount is too large, the scratch resistance deteriorates, so it is desirable to add 5 to 50 parts by weight to 100 parts by weight of the conductive powder.

Further, in the ultraviolet curable conductive coating material according to the present invention, an appropriate amount of a photopolymerization initiator is blended in order to photocur the formed coating film with ultraviolet rays, visible rays or the like. Examples of such a photopolymerization initiator include sulfides such as sodium methyl dithiocarbamate sulfide, diphenyl monosulfide, dibenzothiazoyl monosulfide and disulfide; thioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2 Thioxanthone derivatives such as 4-diethylthioxanthone; azo compounds such as hydrazone and azobisisobutyronitrile; diazo compounds such as benzenediazonium salts; benzoin, benzoin methyl ether, benzoin ethyl ether, benzophenone, dimethylaminobenzophenone, Michler's ketone, benzyl Anthraquinone, t-butylanthraquinone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-aminoanthraquinone, 2-ku Aromatic carbonyl compounds such as Russia anthraquinone; p-dimethylaminobenzoic acid methyl,
Dialkylaminobenzoic acid esters such as ethyl p-dimethylaminobenzoate, butyl p-dimethylaminobenzoate and isopropyl p-diethylaminobenzoate; benzoin peroxide, di-t-butyl peroxide,
Peroxides such as dicumyl peroxide and cumene hydroperoxide; 9-phenylacridine, 9-p-
Acridine derivatives such as methoxyphenylacridine, 9-acetylaminoacridine and benzacridine;
Phenazine derivatives such as 10-dimethylbenzphenazine, 9-methylbenzphenazine and 10-methoxybenzphenazine; 6,4 ′, 4 ″ -trimethoxy-2,3-
Quinoxaline derivatives such as diphenylquinoxaline; 2,
4,5-Triphenylimidazoyl dimer, 2-nitrofluorene, 2,4,6-triphenylpyrylium boron tetrafluoride salt, 2,4,6-tris (trichloromethyl)
Examples include -1,3,5-triazine, 3,3'-carbonylbiscoumarin, and thiomichler ketone. In the present invention, the tin oxide compounded in the UV-curable conductive coating strongly absorbs UV rays having a wavelength of 350 nm or less, and when the thickness is 400 nm or more, the coating film is strongly colored. The maximum absorption wavelength is more preferably in the range of 350 to 400 nm. Further, an amine compound may coexist in order to prevent the sensitivity from being lowered due to oxygen inhibition. Such an amine compound is not particularly limited as long as it is a non-volatile compound such as an aliphatic amine or an aromatic amine. For example, triethanolamine, methyldiethanolamine and the like are often applied, and the dialkylamino compound Amino group-containing photopolymerization initiators such as benzoic acid ester and Michler's ketone can also be used as amines. The addition amount of these photopolymerization initiators is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the conductive powder. Furthermore, 1 to 10 parts by weight is preferable with respect to the (meth) acrylate compound having at least two acryloyl groups or methacryloyl groups in the molecule. If the addition amount is less than 0.1 part by weight, photopolymerization will be slow, and long-time light irradiation is required to satisfy hardness and scratch resistance, and sometimes it remains uncured. Moreover, the addition amount is 10
On the other hand, if the amount exceeds the weight part, the heat resistance and weather resistance of the coating film are deteriorated, and the inconvenience that the conductivity and the wear resistance are adversely affected occurs.

Further, in order to improve the dispersibility and coatability of the above-mentioned conductive powder, an organic solvent is mixed in the ultraviolet curable conductive coating material according to the present invention. It is necessary that the applied organic solvent dissolves the acetal resin. Further, those having a low boiling point or those having a high volatility have a problem that the viscosity of the coating material changes due to evaporation during coating. A solvent of about 180 ° C. is preferable. Examples of such a solvent include methanol,
Examples thereof include ethanol, isopropyl alcohol, cyclohexanone, ethylene glycol monomethyl ether (methyl cellosolve), ethylene glycol monoethyl ether (ethyl cellosolve), diethylene glycol dimethyl ether, butyl acetate, isopropyl acetone, methyl ethyl ketone, and anisole.

In addition to the components described above, various additives such as an ultraviolet absorber, an antioxidant, a thermal polymerization inhibitor, a leveling agent and the like may be added.

In the preparation of the ultraviolet-curable conductive coating composition, a conductive powder containing tin oxide as a main component and a (meth) acrylate compound having at least two acryloyl groups or methacryloyl groups in the molecule are mainly used. A coating binder as a component, a dispersant consisting of an acetal resin, a photopolymerization initiator, and, with respect to an organic solvent and the like, equipment normally used for dispersing or blending the coating material in order to sufficiently disperse the fine powder in the coating material, for example, , Sand mill, ball mill,
It is carried out using an attritor, a high-speed rotary stirring device, a triple roll, or the like.

[0020]

According to the first aspect of the present invention, the ultraviolet curable conductive coating material constituting the antistatic transparent cured coating film of the antistatic transparent conductive plate is mainly composed of tin oxide containing antimony oxide and has a particle size thereof. And a conductive powder having a particle size of 0.01 to 0.4 μm,
Based on 100 parts by weight of the above-mentioned electroconductive powder, a coating binder mainly containing a (meth) acrylate compound having at least two or more acryloyl groups or methacryloyl groups in the molecule: 10 to 100 parts by weight, and an acetal resin. Dispersant: 5 to 50 parts by weight, and photopolymerization initiator:
0.1 to 10 parts by weight and organic solvent: 100 to 1000 parts by weight, and the blended acetal resin acts to bring the viscosity of the ultraviolet curable conductive coating material into a suitable state suitable for coating. It is possible to set and based on this, improve the smoothness of the antistatic transparent cured coating film provided on the transparent conductive plate.

[0021]

EXAMPLES The present invention will be described in more detail with reference to specific examples.

Example 1 Acrylic fiber (diameter 4
0 μm), 50 using weft copper fibers (diameter 40 μm)
A conductive mesh is produced by weaving a mesh woven cloth, and the conductive mesh is sandwiched between two acrylic resin plates having a thickness of 3 mm, and heated to 160 ° C. with a hot press to form a conductive mesh.
Two acrylic resin plates were melted under pressure of 0 kg / cm ² to produce a transparent conductive plate 1 integrated with the conductive mesh embedded therein (see FIG. 1).

On the other hand, an ultraviolet curable conductive coating material was prepared. That is, 100 parts by weight of an antimony oxide-containing tin oxide powder (T-1, manufactured by Mitsubishi Materials) having a primary particle size of 0.02 μm, an acetal resin (S-REC BH- manufactured by Sekisui Chemical Co., Ltd.)
5) 10 parts by weight, dipentaerythritol hexaacrylate 40 parts by weight, hydroquinone 0.1 part by weight, ethyl cellosolve 250 parts by weight, 2,4-diethylthioxanthone 1 part by weight, and dimethylaminoacetophenone 1
Part by weight is placed in an attritor and dispersed for 10 hours.
An ultraviolet curable conductive paint having a paint viscosity of 150 cps was prepared.

This ultraviolet-curable conductive coating material was applied to one surface of the transparent conductive plate 1 by a roll coater so that the film thickness when dried was 1.5 μm, and dried with hot air at 50 ° C. for 10 minutes. Next, using a high-pressure mercury lamp, the irradiation dose is 1
Ultraviolet rays were radiated to 800 mJ / cm ² to cure the coating film of the ultraviolet curable conductive coating material to form an antistatic transparent cured coating film 2 as shown in FIG. 1.

After forming the antistatic transparent cured coating film 2 on both surfaces of the transparent conductive plate 1, the surface is finished by buffing to prepare the antistatic transparent conductive plate 3 shown in FIG.

The surface resistivity of this antistatic transparent conductive plate is ASTM-D257, and the total light transmittance is ASTM.
Each measurement was performed by the test method based on -D1003. In addition, as a scratch resistance, steel wool (# 000
0), the haze value after rubbing 100 times with a load of 500 g was measured and used as a substitute evaluation. Further, the above antistatic transparent cured coating film was visually observed, and when the transparent conductive plate looked distorted, it was evaluated as x, and when it was not distorted, it was evaluated as o.

The results are shown in Table 1 below.

[Example 2] Tin oxide powder containing antimony oxide having a primary particle size of 0.02 µm (manufactured by Mitsubishi Materials, T-
1) 100 parts by weight, 13 parts by weight of acetal resin having a residual hydroxyl content of 35 mol% (Eslec BH-5 manufactured by Sekisui Chemical Co., Ltd.), 15 parts by weight of pentaerythritol triacrylate, 22 parts by weight of pentaerythritol tetraacrylate, 0.1 part by weight of hydroquinone, Ethyl cellosolve 24
0 parts by weight, 1 part by weight of 2,4-diethylthioxanthone,
Also, an antistatic transparent conductive plate similar to that of Example 1 was prepared except that an ultraviolet curable conductive paint having a paint viscosity of 190 cps prepared using 1 part by weight of ethyl p-dimethylaminobenzoate was applied.

The surface resistivity, total light transmittance, and haze value after rubbing of this antistatic transparent conductive plate were measured in the same manner as in Example 1, and the antistatic transparent cured coating film was visually observed. I went. The results are shown in Table 1.

Comparative Example 1 Tin oxide powder containing antimony oxide having a primary particle size of 0.02 μm (T-made by Mitsubishi Materials)
1) 30% by weight of 2-hydroxyethyl acrylate and 70% by weight of methyl methacrylate based on 100 parts by weight
60 parts by weight of a copolymer containing, and cyclohexanone 3
A conductive paint having a paint viscosity of 20 cps was prepared by using 100 parts by weight, and the paint was applied to one surface of the transparent conductive plate by a spray method so that the film thickness after drying was 1.5 μm, and then dried at room temperature for 24 hours. To form a coating film.

Next, after forming the coating film on both surfaces of the transparent conductive plate, the coating film was finished by buffing to prepare an antistatic transparent conductive plate.

For this antistatic transparent conductive plate, the surface resistivity, total light transmittance, and haze value after rubbing were measured in the same manner as in Example 1, and the antistatic transparent cured coating film was visually observed. I went. The results are shown in Table 1.

Comparative Example 2 The surface specific resistance value, total light transmittance, and haze value after rubbing of the transparent conductive plate produced in Example 1 were measured without antistatic treatment.
The results are shown in Table 1.

[0034]

[Table 1] "Evaluation" In Examples 1 to 2, the surface resistivity, the total light transmittance, and the haze value after rubbing were all good, and the antistatic transparent cured coating film had good smoothness, so it was transparent. The conductive plate did not look distorted.

On the other hand, the antistatic transparent conductive plates according to Comparative Examples 1 and 2 were inferior to the Examples in the surface specific resistance value and the haze value after rubbing, and the antistatic transparent sheets according to Comparative Example 1 were used. Regarding the conductive plate, the transparent conductive plate looked distorted because the smoothness of the antistatic transparent cured coating film was not good.

[0036]

According to the first aspect of the present invention, the acetal resin contained in the ultraviolet curable conductive coating acts to make the viscosity of the ultraviolet curable conductive coating suitable for coating. And based on this, it is possible to improve the smoothness of the antistatic transparent cured coating film provided on the transparent conductive plate.

Therefore, there is an effect that an antistatic transparent conductive plate can be provided in which the transparent conductive plate does not appear distorted.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of an antistatic transparent conductive plate according to an example.

2A to 2C are explanatory views of a conductive mesh incorporated in a conventional transparent conductive plate.

[Explanation of symbols]

 1 Transparent conductive plate 2 Antistatic transparent cured coating film 3 Antistatic transparent conductive plate

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location C09D 5/24 PQW 159/00 PHA H01B 5/14 A

Claims (1)

[Claims] 1. A transparent conductive plate having a conductive mesh formed by incorporating a plurality of conductive wires and electric insulating wires which do not intersect each other in a net shape on a base portion made of a transparent electric insulating material, and the transparent conductive plate. An antistatic transparent conductive plate comprising an antistatic transparent cured coating film formed by curing an ultraviolet curable conductive coating material applied on a plate, wherein the ultraviolet curable conductive coating material is an antimony oxide-containing oxide. A conductive powder containing tin as a main component and having a particle size of 0.01 to 0.4 μm, and at least two or more acryloyl groups or methacryloyl groups in the molecule are added to 100 parts by weight of the conductive powder (meth). ) A coating binder containing an acrylate compound as a main component: 10 to 100 parts by weight, a dispersant comprising an acetal resin: 5 to 50 parts by weight, and a photopolymerization initiator: 0.1 to 1
An antistatic transparent conductive plate comprising 0 parts by weight and 100 to 1000 parts by weight of an organic solvent.