JPH0637361Y2 - Antistatic multi-layer antireflection light transmission plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a plastic light-transmitting plate having a neutralizing property. More specifically, it relates to a light transmitting plate that can effectively shield static electricity generated from a display or television cathode ray tube (CRT).

[Prior Art] Since office automation equipment, such as displays for word processors and various computers, game consoles, and cathode ray tubes for televisions, use cathode rays, static electricity is easily generated on the image display device and dust and the like adhere to it. Easy to do. Then, if dust is attached, the image becomes very difficult to see. Also, due to the adhesion of dust etc. to the operator charged to the opposite potential as the CRT,
It has also been pointed out to the operator that it causes skin irritation and eye congestion.

In addition, the static electricity generated from CRTs can sometimes cause discomfort due to electric shock.

Therefore, various improvements have been made in the past to remove such static electricity. An effective means is to cover it with a conductor such as metal. For example, sticking carbon on the surface of thin fibers to make a mesh structure,
Some products, such as Chori Co., Ltd.'s product name "eye saver", have metal wires introduced inside laminated glass. However, these methods have a drawback in that it is difficult for a user such as a word processor to see because a portion that does not transmit the light generated from the display is generated. As another known example, there is proposed a technique in which a conductive material is vapor-deposited on a glass substrate at a high temperature (Japanese Patent Publication No. Sho 49-1844).
In this method, many plastic substrates are softened or melted by this method, and the drawback that the surface is easily scratched cannot be improved and cannot be used.

Therefore, there is no effective technique for the transparent plate made of plastic, and no improvement has been made at present.

The present inventors have already proposed an electromagnetic wave shielding type light transmitting plate (Japanese Patent Laid-Open No. 61-245449), but this technology has an over-spec thickness when viewed from the electromagnetic shielding property of antistatic property. Therefore, there is a problem that the cost is high.

The present invention is a further improvement of this technique.

[Problems to be Solved by the Invention] The present invention provides a technique for remedying the drawbacks of the conventional techniques. In other words, by providing a multilayer antireflection layer on the surface layer using a transparent plastic plate and providing a conductive layer on a part of it, we provide a technology that can effectively exhibit antireflection and antistatic properties (antistatic properties). To do.

[Means for Solving Problems] In order to achieve the above object, the present invention has the following configuration.

"In a light transmitting plate having a hard coat layer having abrasion resistance on a transparent plastic substrate and a multilayer antireflection layer provided on the surface thereof, the outermost layer of the multilayer antireflection layer is a layer having a low refractive index. And the inner layer is provided with a relatively higher refractive index layer than the low refractive index layer, and a transparent conductive film having a film thickness in the range of 2 to 50 nm in a portion of the relatively higher refractive index layer that is not in contact with the hard coat layer. A multi-layer antireflection light-passing plate having antistatic properties, which is characterized in that it is arranged. ”In the present invention, it is first necessary to provide a hard coat layer having abrasion resistance on a plastic transparent substrate. Here, the plastic may be any known material. Further, the transparent substrate may be any as long as light can pass therethrough.

When used on the front surface of a display such as a word processor, it is preferable that the visible light transmittance is 25 to 70% by dyeing or dyeing. This is to reduce eye fatigue.

The abrasion-resistant hard coat layer refers to a coating layer having high hardness such as polyorganosiloxane, silica, or alumina, or a layer containing an acrylic component. This is because the surface of a plastic product is generally easily scratched, so that the surface of the plastic product is improved and the adhesion is improved by undercoating the multilayer antireflection layer coated on the surface layer. And particularly preferably, the hard coat layer is a polyorganosiloxane obtained by coating a silane compound such as methyltrimethoxysilane and vinyltriethoxysilane, or a hydrolyzate thereof, followed by heat condensation.

The preferable film thickness of the hard coat layer is about 1 to 10 μm.

The acrylic hard coat layer refers to a layer obtained by cross-linking an acrylic compound such as methacrylic acid with an ester compound of a polyfunctional glycol such as pentaerythritol or glycerin.

Next, in the present invention, a multilayer antireflection layer is provided on the surface of the hard coat layer. This is to effectively prevent reflection.

A feature of the present invention is that a transparent conductive film is provided on a part of the antireflection layer that is not in contact with the hard coat layer. That is, the multilayer antireflection film of the present invention comprises at least a high refractive index layer and a low refractive index layer thereover, and a transparent conductive film is formed on a portion of the multilayer antireflection layer which is not in contact with the hard coat layer. Is arranged. By doing so, a part of the layer forming the high refractive index layer is replaced with the transparent conductive film, so that the optical characteristics can be prevented from being impaired. The conductive layer generally has a high refractive index, and for example, the ITO layer has a refractive index of about 2.0.

As the transparent conductive layer, any material such as In ₂ O ₃ (indium oxide) and SnO ₂ (tin oxide) may be used as long as it can transmit visible light, but In ₂ O is preferable.
_It is a mixture of ₃ (indium oxide) and SnO ₂ (tin oxide) (hereinafter referred to as ITO). This is because it has high conductivity, can effectively shield static electricity, and has high visible light transmittance. That is, the ITO film is bright and not colored, has excellent transparency, has high electric conductivity, and has excellent overall balance. The thickness of the ITO layer is 2-50 nm
(20 to 500Å) is preferable. If the film thickness is less than 2 nm, it is difficult to effectively shield static electricity, and if it exceeds 50 nm, it becomes difficult to adjust the optical characteristics, and the economic merit is lost.

The transparent conductive film having the above-mentioned thickness is not provided as an independent layer. For example, in order to form a high refractive index layer, a TiO ₂ layer and an equivalent film are provided with a total thickness of λ / 2, or a medium refractive index is used. It is recommended that the SiO ₂ layer and the equivalent film be provided to have a total thickness of λ / 4 in order to form a rate layer.

The transparent conductive film is formed by the so-called low temperature sputtering method,
150 ℃ by vacuum deposition method applying high frequency plasma method
It can be carried out under the following temperature conditions, and a thin film having satisfactory performance can be obtained. Generally, the vapor deposition method is economically advantageous in forming a multilayer reflective film.

Next, in the present invention, it is necessary to provide a low refractive index layer on the surface layer of the high refractive index layer including the conductive layer. This is because the antireflection effect is exerted.

The low refractive index layer may be any known layer such as SiO ₂ or magnesium fluoride, but is preferably a layer containing inorganic silica. Such an inorganic silica layer,
It can be obtained by sputtering silica or by vacuum evaporation. The film thickness may be any thickness as long as it can prevent reflection of visible light.

In the present invention, the low refractive index means a refractive index of less than 1.5 measured under normal conditions using visible light.

In the present invention, the above-mentioned lamination is made of a plastic substrate.
Provided on one side or two sides When it is provided on one surface, it is preferable to provide at least the first layer hard coat described above in order to prevent scratches on the opposite side. Further, an antireflection layer is provided on the surface of the hard coat layer. Is.

Further, as the outermost layer, a film made of a silicone resin or a film made of a fluorine resin may be provided to impart antifouling property.

In the present invention, by attaching the ground wire,
More effective electrostatic shielding. In this case, the ground wire may be taken out from the transparent conductive film, but the purpose can be sufficiently achieved by taking it out through the outermost layer such as the antireflection film layer.

This will be described below with reference to the drawings.

1 to 4 show a cross section of one embodiment of a light transmitting plate which is preferably used as a light transmitting plate having preferable antistatic property and antireflection property of the present invention.

That is, in FIGS. 1 and 2, a hard coat layer 2 is provided on a plastic substrate 1, and a medium refractive index layer (here, the medium refractive index layer has a higher refractive index than the low refractive index layer A, A layer having a lower refractive index than the high refractive index layer B.) C, a high refractive index layer (including the transparent conductive film 10 in part) B, and a low refractive index layer A are provided in this order.

FIG. 3 is a view showing a part of the basic technical idea of the present invention, in which a high refractive index layer (including a transparent conductive film 10 in part) B and a low refractive index layer A are formed on the hard coat layer 2. Are provided in this order.

In FIG. 1, the middle refractive index layer C is a diconium oxide layer 3
And a silicon dioxide layer 4 having a film thickness of λ / 4 are preferable. The high refractive index layer B is composed of a TiO ₂ layer 5 and an ITO film 10,
A film having a film thickness of λ / 2 is preferable. The low refractive index layer A is the SiO ₂ layer 7
It is preferable that the film thickness of is λ / 4.

FIG. 2 shows the high refractive index layer B of FIG. 1 in which the order of the TiO ₂ layer 5 and the ITO film 10 is replaced. The numbers in FIGS. 2 to 3 indicate the same layers as in FIG.

The use of the light transmitting plate having the electrostatic shielding property of the present invention is as follows.
It is particularly effective as a screen filter for TVs and displays (so-called optical filter). It can also be expected to be used as lenses for eyeglasses, films, and molded products for show windows.

[Examples] Examples will be described below.

Example 1 A commercially available polymethylmethacrylate cast plate (“Acrylite” (registered trademark) LN-084 manufactured by Mitsubishi Rayon Co., Ltd., a gray original material, thickness of about 2 mm) was used as a substrate.
As the hard coat paint, as described in Example 1 of JP-A-59-114501, vinyl triethoxysilane is hydrolyzed with glacial acetic acid aqueous solution, and methyl triethoxysilane is hydrolyzed with glacial acetic acid aqueous solution. The materials were mixed and used. Sodium acetate as a curing agent was added to this mixed solution, and a silicone-based surfactant was further added to give a final coating.

This paint was applied to the surface of the substrate and cured by heating to form a cured film having a thickness of about 2 μm. The hard-coated substrate obtained above was set in a vacuum vapor deposition device (HMC-2200 manufactured by Vacuum Instrument Co., Ltd., Kaufman type ion gun and high-frequency coil are installed), and first, as a treatment of the hard-coated surface. Acceleration voltage in an atmosphere with a vacuum of about 2 × 10 ^-5 Torr
Irradiation with an ion beam of argon was performed for 9 minutes under the condition of 600V. Next, zirconium oxide was vapor-deposited as a first layer of the multilayer deposited film under the condition of a vacuum degree of about 4 × 10 ^-5 Torr (oxygen introduction), and silicon dioxide was deposited as a second layer under the condition of about 2 × 10 ^-5 Torr. As the third layer, titanium dioxide was deposited as the third layer under the conditions of about 5 × 10 ⁻⁵ Torr (oxygen introduction) while irradiating the argon ion beam under the acceleration voltage of 600V. Further as the fourth layer
About 1.5 × 10 ^-4 ITO (a mixture of indium oxide and tin oxide)
Under the condition of Torr (introduction of oxygen), high-frequency (13.56MHz) 200W was applied for vapor deposition in a generated plasma atmosphere, and then silicon dioxide was used as the fifth outermost layer under the condition of about 2 × 10 ^-5 Torr. It was vapor-deposited. The set temperature during vapor deposition was 60 ° C, and the optical film thickness of each layer was λ / 4 × 0.35, λ
/4×0.35, λ / 4 × 1.67, λ / 4 × 0.15, λ / 4 × 1.00 (where λ = 480 nm) were controlled using an optical monitor. The ITO film had a thickness of about 10 nm.

The product of the present invention obtained by the above processing has an extremely hard surface (although scratches are observed even after 5 reciprocating abrasions with # 0000 steel wool under a load of about 1 kg / cm ² ). Also, the anti-reflection curing of the vapor-deposited multilayer film is excellent, the reflectance at a wavelength of 550 nm is about 2.0%, and the electrostatic chargeability when the surface was rubbed with a tissue paper was evaluated with a foil electroscope. I was not able to admit.
Further, in the same manner as above, except that the ITO layer of the fourth layer is not provided on the surface of the base material obtained above, which is opposite to the surface provided with the hard coat layer, etc. Layers.

The resulting light transmitting plate is more than the light transmitting plate obtained above.
It was excellent in antireflection performance.

The product of the present invention was suitable because it was excellent in anti-reflection and static electricity could be removed by using the VDT front filter ground.

A schematic cross-sectional view of the light transmitting plate obtained in this example is shown in FIG.

Example 2 A multilayer antireflection light transmitting plate was prepared in which the third layer and the fourth layer vacuum-deposited among the various processing conditions shown in Example 1 were changed as follows. That is, ITO is used as the third layer in an amount of about 1.5 × 10 ^-4
Vapor deposition was performed in a plasma atmosphere generated by applying high frequency (13.56MHz) 200W under Torr (oxygen introduction), and the fourth layer was accelerated at 600V under about 5 × 10 ^-5 Torr (oxygen introduction). Titanium dioxide was vapor-deposited while being irradiated with an argon ion beam. The set temperature during vapor deposition is 70 ° C from the first layer to the final fifth layer, and the optical film thickness of each layer is λ / 4 × 0.35, λ / 4 × 0.35, λ / 4 × in order from the first layer on the base side. 0.25, λ / 4 x 1.58, λ
It was controlled by an optical monitor to be /4×1.00 (where λ = 480 nm). Further, a hard coat layer and an antireflection layer are provided in the same manner except that the ITO layer is not provided on the surface of the substrate obtained above that is opposite to the surface provided with the hard coat layer or the like. It was

The surface hardness, the antireflection effect, and the antistatic effect of the product of the present invention obtained by performing the above-mentioned processing were the same as those prepared in Example 1, and were suitable as a VDT front filter.

FIG. 2 shows a schematic cross-sectional view of the light transmitting plate obtained in this example.

Comparative Example 1 Of the various processing conditions shown in Example 1, processing was performed under exactly the same conditions except for the antireflection layer, that is, the substrate, hard coat, and pretreatment for vapor deposition. Below this, the vacuum deposition conditions are: ITO as the first layer of the multilayer deposition film, deposited under a plasma atmosphere generated by applying high frequency (13.56MHz) 200W under the condition of about 1.5 × 10 ^-4 Torr (introduction of oxygen). Then, zirconium oxide is vapor-deposited as a second layer under the condition that the degree of vacuum is about 4 × 10 ⁻⁵ Torr (oxygen introduction), and silicon dioxide is about 2 × 10 ⁻⁵ as a third layer.
Vapor deposition was performed under the conditions of Torr, and titanium dioxide was vapor-deposited as the fourth layer under the conditions of approximately 5 × 10 ⁻⁵ Torr (introduction of oxygen) at an accelerating voltage of 600 V under irradiation with an argon ion beam. Then, as the fifth outermost layer, about 2 × 10 ^{−5 of} silicon dioxide was used.
Deposition was carried out under the conditions of Torr. All set temperatures during vapor deposition
60 ℃, the optical thickness of each layer is λ / 4 × 0 from the base side.
15, λ / 4 × 0.15, λ / 4 × 0.40, λ / 4 × 1.80, λ / 4 × 1.00
(However, λ = 480 nm) was controlled using an optical monitor.

An outdoor exposure test was conducted as a comparative evaluation of the film physical properties of the antireflection layer of the light transmitting plate and the light transmitting plates of Examples 1 and 2 of the present invention.

In order to irradiate the light-transmitting plate efficiently with sunlight, the light-transmitting plate was attached to the south side and at an angle of 45 degrees from the ground, and the antireflection layer surface having the conductive film was attached to the sun side. After exposure for 1 month, an adhesion test was conducted. As a result, the antireflection layer of the light transmitting plate of the present invention was not peeled off, but it was peeled off in the case of Comparative Example 1.

Here, the adhesion test was performed as follows.

Adhesion test Cellophane tape (manufactured by Nichiban) was attached to the film surface to be evaluated, and peeled off by pulling in a direction of 45 degrees from the film surface. This 3
Repeatedly, it was observed whether the film peeled off with the cellophane tape.

[Effects of the Invention] The present invention uses a transparent plastic plate to provide a multi-layer antireflection layer on the surface layer and a conductive layer on a part of the surface layer, thereby effectively providing antireflection and antistatic properties (antistatic property). And static electricity shielding property) are exhibited.

[Brief description of drawings]

1 to 3 show a cross section of one embodiment of a light transmitting plate which is preferably used as a light transmitting plate having preferable antistatic property and antireflection property of the present invention. That is, in FIGS. 1 and 2, a hard coat layer 2 is provided on a plastic substrate 1, on which a medium refractive index layer C, a high refractive index layer (including a transparent conductive film 10 in part) B, and a low refractive index layer are provided. A is provided in this order. FIG. 3 is a view showing the basic technical idea of the present invention, in which a high refractive index layer (including a transparent conductive film 10 in part) B and a low refractive index layer A are arranged in this order on the hard coat layer 2. It was provided in.

Claims (8)

[Scope of utility model registration request] 1. A light-transmitting plate comprising a plastic transparent substrate, a hard coat layer having abrasion resistance, and a multilayer antireflection layer formed on the surface thereof, wherein the outermost layer of the multilayer antireflection layer has a low refractive index. Index layer, and provided with a relatively higher refractive index layer than the low refractive index layer in the inner layer, the thickness of the relatively high refractive index layer in the portion not in contact with the hard coat layer is 2 to 50 nm.
A multilayer antireflection light-transmitting plate having a charge eliminating property, characterized in that a transparent conductive film in the range of 10 is arranged. 2. A multilayer antireflection light-transmitting plate having static elimination property according to claim (1) of the utility model registration, wherein the conductive film layer is a layer containing indium oxide and tin oxide. 3. A multilayer antireflection light-transmitting plate having static elimination property according to claim (1) of the utility model registration, wherein the hard coat layer is a layer containing an organic polysiloxane. 4. A multilayer antireflection light-transmitting plate having a charge eliminating property according to claim (1) of the utility model registration, characterized in that the transparent base material is colored. 5. The utility model registration claim (1), wherein the layer having a relatively high refractive index includes a layer composed of a titanium oxide layer or a zirconium oxide layer and a transparent conductive film layer. A multilayer antireflection light-transmitting plate having a static eliminating property. 6. The utility model registration claim (1), wherein the relatively high refractive index layer includes an inorganic silica layer or a magnesium fluoride layer and a layer formed of a transparent conductive film. A multilayer antireflection light-transmitting plate having a static eliminating property. 7. A multilayer antireflection light having a static elimination property according to claim (1) of the utility model registration, wherein the outermost layer having a low refractive index is an inorganic silica layer or a magnesium fluoride layer. Transparent plate. 8. A multilayer antireflection light having a static eliminating property according to claim (1) of the utility model registration, characterized in that a ground wire is drawn out through the outermost layer of the multilayer antireflection layer. Transparent plate.