JPH1177873A - Reflection preventing laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain electromagnetic shielding effect simultaneously with sufficient reflection preventing effect by setting the sheet resistance value of a ceramic membrane layer having conductivity to a specific value or less. SOLUTION: In a reflection preventing laminate, a ceramic membrane layer 2 consisting of at least three layers or more is provided on a base material 1 and at least one layer constituting the ceramic membrane layer 2 has conductivity. The ceramic membrane layers 3-6 used in the ceramic membrane layer 2 are composed of inorg. compds. and different in refractive index by the materials thereof and the reflection preventing laminate can be obtained by laminating a plurality of ceramic membrane layers different in refractive index in specific film thicknesses. The conductive ceramic membrane 3 having at least one ceramic layer having conductivity is based on either one of indium oxide, zinc oxide and tin oxide or a mixture two or three kinds of them and the sheet resistance value thereof is set to 200 Ω/sq. or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a computer display, a cathode ray tube of a television, and a laminate having an antireflection function mounted on the whole surface of various display screens for the purpose of reducing light reflection.

[0002]

2. Description of the Related Art Conventionally, in a cathode ray tube of a television or the like, a multilayer film is coated by a vacuum deposition method or the like as a means for preventing reflection on the surface and a means for blocking electromagnetic waves. Further, in the liquid crystal screen, irregular reflection is made by providing irregularities on those surfaces.

An example in which a transparent and conductive layer is applied to an antireflection laminate is disclosed in JP-A-5-323101, which is based on indium oxide or tin oxide. In addition, as disclosed in Japanese Patent Application Laid-Open No. 64-80904, a device using a very thin metal film is known.

[0004] In these, indium oxide or tin oxide used as a conductive ceramic thin film layer has a refractive index of about 2.0, and if the number of layers is small, a sufficient antireflection effect cannot be obtained. Was.

[0005] Further, although it varies depending on the frequency band required for use as an electromagnetic wave shield, the material must have a sheet resistance of 1 kΩ / □ or less, preferably 200 Ω / □ or less. Low resistance is required more than prevention materials and transparent electrode materials.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve such problems, and it is an object of the present invention to provide a sufficient anti-reflection effect and an electromagnetic wave shielding effect. An object of the present invention is to provide an antireflection laminate.

[0007]

In order to solve this problem, the present invention has at least three ceramic thin film layers on a substrate, and at least one of the ceramic thin film layers has a ceramic thin film having conductivity. An anti-reflection laminate, which is a layer, wherein the conductive ceramic thin film layer has a sheet resistance of 200 Ω / □ or less.

Further, the ceramic thin film layer having conductivity mainly contains any one of indium oxide, zinc oxide and tin oxide or a mixed oxide of two or three of them, and the base material is a plastic film. That a hard coat layer is formed between the substrate and the ceramic thin film layer, that an antifouling layer is formed on the surface of the ceramic thin film layer, Provided is an antireflection laminate, wherein the refractive index of the high refractive index layer is higher than the refractive index of the high refractive index layer near the surface.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail. FIG. 1 shows an example of a cross-sectional structure of the antireflection laminate of the present invention. As the substrate 1, any material having transparency and a smooth surface may be used, and examples thereof include a polymer film such as a polyester film, a polyolefin film, polycarbonate, triacetyl cellulose, and polyether sulfone, and glass. However, plastic is preferred in view of the overall layer configuration.

The ceramic thin films 3 to 6 used for the ceramic thin film layer 2 of the present invention are made of an inorganic compound.
Thin films made of oxides, sulfides, fluorides, nitrides and the like can be used. The thin film made of the inorganic compound has a different refractive index depending on its material. By stacking a plurality of ceramic thin films having different refractive indices with a specific thickness, it is possible to form an antireflection laminate.

Materials having a low refractive index include magnesium oxide (refractive index = 1.6), silicon dioxide (1.5), magnesium fluoride (1.4), and calcium fluoride (1.3).
To 1.4), cerium fluoride (1.6), aluminum fluoride (1.3) and the like. Materials having a high refractive index include titanium dioxide (2.4), zirconium dioxide (2.0), zinc sulfide (2.3), and tantalum oxide (2.
1), zinc oxide (2.1), indium oxide (2.0)
Is mentioned.

In the present invention, the conductive ceramic thin film in which at least one layer is a conductive ceramic thin film is selected from indium oxide, zinc oxide and tin oxide, or a mixed oxide of two or three of them. Things.

As a method for producing the ceramic thin film layer of the present invention, any film forming method may be used as long as the film thickness can be controlled, and a dry method is particularly suitable. For this, a physical vapor deposition method such as an ordinary vacuum vapor deposition method or a chemical vapor deposition method such as a CVD method can be used.

The antireflection laminate of the present invention may be provided with one or both of a hard coat layer 7 and an antifouling layer 8 as shown in FIG.

As the hard coat layer 7, a material which is transparent so as not to impair the overall transparency and has a refractive index equal to or close to that of the substrate can be used. For example, an ultraviolet curable acrylic or the like can be used. The thickness is desirably 3 to 6 μm.

The antifouling layer 8 can be selected from various compositions according to its use. For example, a furosilane-based one can be used. As a method for providing the antifouling layer, dry processing by CVD is a preferable method particularly suited to the purpose. The thickness is preferably 5 to 15 nm.

[0017]

【Example】

Example 1 100 μm-thick polyethylene terephthalate was used as a substrate, and indium tin oxide 3 was used from the substrate side.
0 nm (refractive index dispersion at a wavelength of 450 to 650 nm is 2.0 to 2.2), silicon dioxide 20 nm, indium tin oxide 70 nm (refractive index dispersion at a wavelength of 450 to 650 nm is 1.9 to 2.1), silicon dioxide 10 nm , Were laminated by vacuum evaporation.

The light reflectance of the obtained film is 450 to 650.
In nm, the wavelength range where the light reflectance is 1% or less is widened by 10% as compared with the case where indium tin oxide having the same refractive index dispersion is used and the average is 0.7% or less. Further, the sheet resistance value was 100Ω / □ or less. A better electromagnetic wave shielding effect (30 dB at a frequency of 100 MHz) was obtained.

Example 2 A hard coat layer made of an ultraviolet-curable acrylic resin having a thickness of 4 μm was provided using triacetyl cellulose having a thickness of 80 μm as a base material, and zinc oxide 25 nm (wavelength 450 to 450 nm) was applied from the base material side. The refractive index dispersion at 650 nm is 1.9 to 2.1), and silicon dioxide 25n
n, zinc oxide 70 nm (refractive index at a wavelength of 450 to 650 nm is 1.8 to 2.0), and silicon dioxide 100 nm are respectively laminated by vacuum evaporation, and C is further used as an antifouling layer.
A 10 nm fluoroalkylsilane was deposited by VD.

The light reflectance of the obtained film is 450 to 650.
The average in nm was 0.4% or less. Further, the sheet resistance value was 100Ω / □ or less. Furthermore, a good electromagnetic wave shielding effect (frequency 100 MH
30 dB) was obtained at z. In addition, the adhesion between the layers was good, and the pure contact angle on the surface was 107 degrees, and water repellency was also obtained.

[0021]

As described above, according to the present invention, it is possible to obtain a laminate having a sufficient anti-reflection effect and a sufficient electromagnetic wave shielding effect.
Further, by providing a hard coat layer and an antifouling layer, the adhesion between layers and the water repellency of the surface could be improved.

[0022]

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an example of a cross-sectional structure of an antireflection laminate according to the present invention.

FIG. 2 is an explanatory view showing another example of the cross-sectional structure of the antireflection laminate according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Base material 2 ... Ceramic thin film 3-6 ... Ceramic thin film layer 7 ... Hard coat layer 8 ... Antifouling layer

Continued on the front page (51) Int.Cl. ⁶ Identification code FI G02B 1/11 H04N 5/72 A H04N 5/72 G02B 1/10 A

Claims (6)

[Claims] An anti-reflection laminate comprising at least three ceramic thin film layers on a substrate, wherein at least one of the ceramic thin film layers is a ceramic thin film layer having conductivity. The sheet resistance value of the ceramic thin film layer having the following is 200Ω / □ or less. 2. The method according to claim 1, wherein the conductive ceramic thin film layer comprises:
2. The anti-reflection laminate according to claim 1, wherein any one of indium oxide, zinc oxide, and tin oxide or a mixed oxide of two or three of them is a main component. 3. The antireflection laminate according to claim 1, wherein the substrate is a plastic film. 4. A hard coat layer is formed between the substrate and the ceramic thin film layer.
4. The antireflection laminate according to any one of items 1 to 3. 5. The antireflection laminate according to claim 1, wherein an antifouling layer is formed on a surface of said ceramic thin film layer. 6. The ceramic thin film layer according to claim 1, wherein the refractive index of the high refractive index layer closer to the substrate is higher than the refractive index of the high refractive index layer closer to the surface. 6. The antireflection laminate according to any one of 5.