JP2000329931A - Optical filter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To design an optical filter in such a manner that silver coagulation by enhancing corrosion resistance to a chloride ion of the optical filter without largely degrading the luminous transmittance. SOLUTION: This optical filter is formed by using a transparent electrically conductive thin film in which a metallic layer 40 is formed on an uppermost transparent thin film layer 20 having high refractive index or between the uppermost transparent thin film layer 20 having high refractive index and a metallic thin film layer 30. The metallic layer 40 is composed of at least one metal other than silver among group IV-XII metals of Periodic Table.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical filter for a display, and more particularly, to an optical filter suitably used for a plasma display panel.

[0002]

2. Description of the Related Art In recent years, as society has become more sophisticated, optoelectronics-related components and equipment have remarkably advanced.
Among them, displays for displaying images have been remarkably popularized for computer monitor devices in addition to conventional television devices. Among them, market demands for larger and thinner displays are increasing. 2. Description of the Related Art Recently, a plasma display panel (PDP) has attracted attention as a display that can be made large and thin. The plasma display panel emits strong electromagnetic waves outside the device in principle. Electromagnetic waves are known to cause damage to instruments, and it has recently been reported that electromagnetic waves may also cause damage to the human body. For this reason, the emission of electromagnetic waves is being regulated in a legal manner. For example,
Currently in Japan, VCCI (VoluntaryCont.)
rolCountil for Interferen
ceby data processing equi
pment electronic office m
regulations, and in the United States, the FCC
(Federal Communication Co
product regulations.

[0003] A plasma display panel emits strong near-infrared rays. The near-infrared rays cause malfunctions of cordless telephones, infrared remote controllers, and the like. Particularly problematic wavelengths are 800 to 1000
nm. In order to suppress the emission of electromagnetic waves and near-infrared rays, there has recently been an increasing demand for optical filters for blocking electromagnetic waves and near-infrared rays. This optical filter needs to have conductivity over the entire surface of the filter and to have excellent transparency. Optical filters that satisfy these requirements and have been put into practical use can be broadly divided into two types. One is a so-called metal mesh type in which metal is thinly arranged in a grid pattern on the entire surface of a substrate. This is excellent in conductivity and has excellent electromagnetic wave blocking ability, but is not excellent in near-infrared reflection ability and transparency, and generates a moiré image. The other is a transparent film type in which a transparent conductive thin film is disposed on the entire surface of a substrate. The transparent conductive thin film type optical filter is inferior to the metal mesh type optical filter in electromagnetic wave blocking ability, but has excellent near-infrared ray blocking ability and transparency, and does not generate a moiré image. It can be suitably used.

A transparent conductive thin film type optical filter is
In many cases, a transparent conductive thin film is bonded to a transparent support substrate via an adhesive. In terms of weight reduction and safety of the display device itself, a polymer molded body is often suitably used as the transparent support substrate, but the transparent polymer molded body is deformed by the influence of heat and moisture. In many cases, glass is used. Further, an optical film having a reflectance reducing function, an anti-glare function or a toning function is often combined with a transparent conductive film and bonded. The lower the sheet resistance of the optical filter, the better the electromagnetic wave blocking ability of the optical filter. As for the transparent conductive thin film type optical filter, it is common practice to obtain a transparent conductive thin film by laminating a metal thin layer having a low resistance.
Among them, a metal thin film made of silver having the lowest specific resistance among pure substances is preferably used. Further, for the purpose of increasing the transmittance and improving the stability of the metal thin film layer, the metal thin film layer is usually sandwiched between transparent high refractive index thin film layers to form a transparent conductive thin film laminate.

[0005] Silver, which is suitably used as a metal thin film layer material because of its low specific resistance, tends to cause atom aggregation. When silver atoms of the silver thin film layer aggregate, a silver white point is generated,
The original high transparency and low resistance are lost. Agglomeration of silver atoms in the silver thin film layer is likely to occur, for example, in the presence of chloride ions. Chloride ions are ubiquitous in the atmosphere. One of the causes is sodium chloride release from the human body or seawater. In a transparent conductive thin film laminate, a transparent high refractive index thin film layer of ITO or the like has the effect of preventing chloride ions or the like from reaching the silver thin film layer, but maintains high transparency due to optical design. In order to do so, the thickness must be reduced to several nm, and the prevention ability is often insufficient.

[0006]

In the conventional optical filter, in the transparent conductive thin film laminate, the silver thin film layer is aggregated with silver atoms under the influence of the environment.

[0007]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that the transparent high-refractive-index thin-film layer on the outermost surface or the transparent high-refractive-index thin-film layer and metal By using a transparent conductive thin film laminate having a metal layer formed between the thin film layer and the transparent conductive thin film, it is possible to create an optical filter that does not cause silver atom aggregation in the silver or silver-containing alloy thin film layer of the transparent conductive thin film. They found what they could do and led to the present invention.

That is, the present invention provides (1) an optical filter having a transparent conductive thin film layer, wherein the transparent conductive thin film layer has a transparent high refractive index on at least one principal surface of the transparent substrate (A). A thin film layer (a), a metal thin film layer (b) made of silver or an alloy containing silver, and 4 of the periodic table.
And a metal layer (c) containing at least one metal other than silver, from among groups A to B, A / b / a / c, A / b
/ C / a, A / a / b / a / c, A / a / b / c / a,
A / b / a / b / a / c, A / b / a / b / c / a, A
/ A / b / a / b / a / c, A / a / b / a / b / c /
a, A / b / a / b / a / b / a / c, A / b / a / b
/ A / b / c / a, A / a / b / a / b / a / b / a /
c, A / a / b / a / b / a / b / c / a, A / b / a
/ B / a / b / a / b / a / c, A / b / a / b / a /
b / a / b / c / a, A / a / b / a / b / a / b / a
/ B / a / c, A / a / b / a / b / a / b / a / b /
c / a, A / a / b / a / b / a / b / a / b / a / b
/ A / c, A / a / b / a / b / a / b / a / b / a /
(2) a metal layer (c) comprising a metal of Group 4 to Group 7 of the periodic table or copper, palladium, platinum,
(1) The optical filter according to (1), wherein the metal layer contains at least one metal selected from gold. (3) The metal layer (c) contains a metal belonging to Groups 4 to 7 of the periodic table. (1) The optical filter according to any one of (2) and (4) the elemental composition of the metal in the metal layer (c) is 3.0% (atomic ratio) or more and 99.9%.
(Atom number ratio) The optical filter according to any one of (1) to (3), wherein the thickness of the metal layer (c) is:
The optical filter according to any one of (1) to (4), which has a thickness of 0.3 nm or more and 10 nm or less. (6) The optical filter according to any one of (1) to (5), wherein the transparent high refractive index thin film layer (a) is made of at least one of indium oxide, tin oxide, and zinc oxide.

(7) The optical filter according to any one of (1) to (6), wherein the cross-sectional structure is an antireflection layer / film substrate / adhesive material layer / transparent conductive thin film layer / film substrate / Adhesive layer / Transparent support substrate, Anti-reflection layer / Film substrate / Adhesive layer / Transparent conductive thin film layer / Film substrate / Adhesive layer
/ Transparent support substrate / Anti-reflective layer, Anti-reflective layer / Film substrate /
Adhesive layer / Transparent conductive thin film layer / Film substrate / Adhesive layer / Transparent support substrate / Adhesive layer / Film substrate / Anti-reflective layer, Anti-reflective layer / Film substrate / Adhesive layer / Film substrate / Transparent conductive thin film Layer / adhesive layer / transparent support substrate, antireflection layer / film substrate / adhesive layer / film substrate / transparent conductive thin film layer / adhesive layer / transparent support substrate / antireflective layer, antireflective layer / film substrate / adhesive Material layer / film substrate / transparent conductive thin film layer / adhesive layer / transparent support substrate / adhesive layer / film substrate / anti-reflective layer,
Anti-reflection layer / Film substrate / Transparent conductive thin film layer / Adhesive layer /
Transparent support substrate, antireflection layer / film substrate / transparent conductive thin film layer / adhesive layer / transparent support substrate / antireflection layer, antireflection layer /
The present invention relates to an optical filter that is any one of a film substrate, a transparent conductive thin film layer, an adhesive layer, a transparent support substrate, an adhesive layer, a film substrate, and an antireflection layer.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The optical filter according to the present invention comprises a transparent conductive thin film, a transparent high refractive index thin film layer (a) and silver or silver on at least one principal surface of a transparent substrate (A). A / b / a / c and A / b / a / c
/ B / c / a, A / a / b / a / c, A / a / b / c /
a, A / b / a / b / a / c, A / b / a / b / c /
a, A / a / b / a / b / a / c, A / a / b / a / b
/ C / a, A / b / a / b / a / b / a / c, A / b /
a / b / a / b / c / a, A / a / b / a / b / a / b
/ A / c, A / a / b / a / b / a / b / c / a, A /
b / a / b / a / b / a / b / a / c, A / b / a / b
/ A / b / a / b / c / a, A / a / b / a / b / a /
b / a / b / a / c, A / a / b / a / b / a / b / a
/ B / c / a, A / a / b / a / b / a / b / a / b /
a / b / a / c, A / a / b / a / b / a / b / a / b
/ A / b / c / a, wherein the transparent conductive thin film (C) is formed on one main surface of the transparent support base (B). ), And the metal thin film layer (b) made of silver or silver alloy of the transparent conductive thin film layer does not cause silver atom aggregation due to chloride ions.

The present invention will be described with reference to the drawings. Figures 1-4
FIG. 1 is a cross-sectional view showing an example of a transparent conductive thin film laminate used for an optical filter for a plasma display panel in the present invention. In FIG. 1, a transparent substrate (A) 1
0, a transparent high-refractive-index thin film layer (a) 20, a metal thin film layer (b) 30, and a metal layer (c) 40 are laminated with a laminated structure A / a / b /
A transparent conductive thin film having a / c is mentioned. The other structure is A / a / b / a / b / a /
c (FIG. 2), A / a / b / a / b / a / b / a / c (FIG. 3), A / a / b / a / b / a / b / a / b / a / c
(FIG. 4).

FIG. 5 is a sectional view showing an example of an optical filter for a plasma display panel according to the present invention. A transparent conductive thin film (C) 60 is bonded to one main surface of the transparent support base (B) 50, and an antireflection film (D) 70 is further bonded thereon and the other main surface. ing. An electrode (E) 80 is formed on an outer peripheral portion on the transparent conductive thin film.

The transparent support used in the present invention preferably has excellent transparency and sufficient mechanical strength. Here, “excellent in transparency” means that the thickness 3
It indicates that the transmittance for light having a wavelength of 400 to 700 nm when the plate is about mm is 50% or more. Preferred materials include polymer moldings and glass.

[0014] The transparent polymer molded article, compared to glass,
It is more preferably used because it is light and hard to crack. An example of a preferred material is polymethyl methacrylate (P
MMA) and other acrylic resins, polycarbonate resins, and the like, but are not limited to these resins. Above all, PMMA can be suitably used because of its high transparency in a wide wavelength range and high mechanical strength. Further, a transparent polymer molded article is often provided with a hard coat layer for reasons such as increasing the hardness or adhesion of the surface. As the hard coat layer material, an acrylate resin or a methacrylate resin is often used, but is not particularly limited. As a method of forming the hard coat layer, an ultraviolet curing method or a polymerization transfer method is often used, but is not particularly limited thereto. In the polymerization transfer method, a target material is limited to a cell cast polymerization material such as a methacrylate resin, but a hard plate layer can be formed with very high productivity by a continuous plate making method. For this reason, the formation of the methacrylate resin layer by the polymerization transfer method is the most suitably used method of forming a hard coat layer.

Glass is less likely to change in shape due to heat and moisture, and is therefore suitably used for optical applications that require delicate precision. In order to have mechanical strength, a chemical strengthening process or an air-cooling strengthening process is performed, and it is usually used as semi-tempered glass or tempered glass. There is no particular limitation on the thickness of the transparent support substrate, as long as it has sufficient mechanical strength and rigidity to maintain flatness without sagging. Usually, 1 to
It is about 10 mm. In the present invention, a transparent conductive thin film is bonded to the transparent support substrate.
The transparent conductive thin film has an ability to block electromagnetic waves and near infrared rays, and is indispensable for the optical filter in the present invention. This transparent conductive thin film is
It is usually obtained by forming a transparent conductive thin film layer on a polymer film.

An antiglare film or an antireflection film may be used as a transparent conductive thin film substrate, and a transparent conductive thin film layer may be formed on the opposite surface of the antiglare layer or the antireflection layer, respectively. In the past, anti-glare and anti-reflective properties were often given to a film for protecting the transparent conductive thin film layer to enhance visibility, but the anti-glare film and reflective The use of a protective film is very useful because this function can be maintained without using a protective film. Further, an anti-glare film or an anti-reflection film is bonded to the surface opposite to the surface where the transparent conductive thin film is bonded on the transparent support base to further enhance visibility, or an anti-glare layer or an anti-reflection layer is formed directly. No problem.

The material of the polymer film used as the substrate of the transparent conductive thin film, the antiglare film and the antireflection film is not particularly limited as long as it has transparency. Specifically, polyimide, polysulfone (PS
F), polyether sulfone (PES), polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), polycarbonate (PC), polyether ether ketone (PEEK), polypropylene (P
P), triacetyl cellulose (TAC) and the like. Among them, polyethylene terephthalate (PET) and triacetyl cellulose (TAC) are particularly preferably used.

The antiglare film is a film having fine irregularities of about 0.1 to 10 μm on its surface and transparent to visible light. Specifically, an acrylic resin, a silicone resin, a melamine resin, a urethane resin, an alkyd resin, a thermosetting resin or a photocurable resin such as a fluorine resin,
Disperse particles of inorganic or organic compounds such as silica, melamine, acrylic, etc. into an ink and apply it on a transparent polymer film by bar coating, reverse coating, gravure coating, die coating, roll coating, etc. Let it cure. The average particle size of the particles is 1 to 40 μm. Or, an acrylic resin, a silicon resin, a melamine resin, a urethane resin, an alkyd resin, a thermosetting or photocurable resin such as a fluorine resin is applied to the substrate,
An antiglare film can also be obtained by pressing and curing a mold having a desired haze or surface condition. Furthermore, like etching a glass plate with hydrofluoric acid,
An antiglare film can also be obtained by treating a base film with a chemical. In this case, the haze can be controlled by the processing time and the etching property of the chemical. In the above-described antiglare film, it is only necessary that appropriate irregularities are formed on the surface, and the production method is not limited to the methods described above. The haze of the antiglare film is from 0.5% to 20%, preferably 1%.
% Or more and 10% or less. If the haze is too small, the antiglare performance is insufficient, and if the haze is too large, the parallel light transmittance is reduced, and the visibility of the display deteriorates. This antiglare film can be used as an anti-Newton ring film in many cases.

The antireflection film is a film in which an antireflection layer is formed on a polymer film, and the surface on which the antireflection layer is formed has a visible light reflectance of 0.1% or more.
%, Preferably 0.1% or more and 1.5% or less, more preferably 0.1% or more and 0.5% or less. The visible light reflectance of the surface on which the anti-reflection film is formed is determined by roughening the opposite surface (the surface on which the anti-reflection film is not formed) with sandpaper and eliminating the reflection on the opposite surface by black paint to prevent reflection. It can be known by measuring reflected light generated only on the surface on which the film is formed.

As the anti-reflection layer, specifically, a fluorine-based transparent polymer resin, magnesium fluoride, or silicon-based resin having a refractive index of 1.5 or less, preferably 1.4 or less in the visible light region. For example, 1 /
Four-wavelength optical film with a single layer, different refractive index, metal oxides, fluorides, silicides, borides, carbides, nitrides, inorganic compounds such as sulfides, silicon-based resins and acrylic resins, There is a laminate in which two or more thin films of an organic compound such as a fluororesin are laminated. Although a single layer is easy to manufacture, the antireflection property is inferior to that of a multilayer laminate. The multilayer laminate has an antireflection function over a wide wavelength range, and there is little restriction on optical design due to the optical characteristics of the base film. For the formation of these inorganic compound thin films,
Conventionally known methods such as sputtering, ion plating, ion beam assist, vacuum deposition, and wet coating may be used.

In the present invention, the basic structure of the transparent conductive thin film layer (layer structure excluding the metal layer (c)) is a laminate of a transparent high refractive index thin film layer and a silver or silver alloy thin film layer. Although a single layer of a transparent conductive thin film can provide an electromagnetic wave shielding effect to some extent, it is not sufficient, and usually a transparent high-refractive-index thin film and a metal thin film are laminated in a film thickness combination that provides sufficient transmittance and surface resistance. can get. A silver or silver alloy thin film is particularly preferably used as a metal thin film because it has a lower specific resistance and excellent light transmittance as compared with other metal thin films. The transmittance of the basic configuration of the transparent conductive thin film layer is preferably 40% or more and 99% or less, more preferably 50% or more and 99%.
Or less, more preferably 60% or more and 99% or less. Further, a preferable surface resistance value is 0.2 (Ω / □) or more and 100 (Ω / □) or less, preferably 0.2 (Ω / □).
□) or more and 10 (Ω / □) or less, more preferably,
0.2 (Ω / □) or more and 3 (Ω / □) or less, still more preferably 0.2 (Ω / □) or more and 0.5 (Ω / □)
It is as follows.

The transparent high refractive index thin film layer (a), the metal thin film layer (b) and the metal layer (c) are placed on the transparent polymer molded body substrate (A) as shown in the sectional views of FIGS. A transparent conductive thin film can be obtained by laminating the films. It is preferable that the material used for the transparent high-refractive-index thin film layer (a) has excellent transparency as much as possible. Here, “excellent in transparency” means that when a thin film having a thickness of about 100 nm is formed, the transmittance of the thin film to light having a wavelength of 400 to 700 nm is 60% or more. The high refractive index material has a refractive index for light of 550 nm,
1.4 or more materials. These may be mixed with impurities depending on the application.

Suitable for use as a transparent high refractive index thin film layer
An example of a material that can be used is the oxidation of indium and tin.
(ITO), oxide of cadmium and tin (CT
O), aluminum oxide (Al_TwoO_Three), Zinc oxide (Zn
O_Two), Oxides of zinc and aluminum (AZO), acids
Magnesium oxide (Mg0), thorium oxide (Th
0_Two), Tin oxide (SnO)_Two), Lanthanum oxide (La
O_Two), Silicon oxide (SiO_Two), Indium oxide (I
n_TwoO_Three), Niobium oxide (Nb_TwoO_Three), Antimony oxide
(Sb _TwoO_Three), Zirconium oxide (ZrO)_Two), Oxide
Cium (CeO)_Two), Titanium oxide (TiO)_Two), Bis oxide
Trout (Bio_Two).

Further, a transparent high refractive index sulfide may be used. Specific examples include zinc sulfide (ZnS), cadmium sulfide (CdS), and antimony sulfide (Sb ₂ S ₃ ). Among transparent high-refractive index materials, among others, IT
O, TiO ₂ and ZnO are particularly preferred. ITO and Zn
O ₂ has conductivity and a refractive index in the visible region as high as about 2.0, and has almost no absorption in the visible region. TiO ₂ is an insulator and has a slight absorption in the visible region, but has a large refractive index for visible light of about 2.3.

The material of the metal thin film layer (b) used in the present invention is preferably a material having as high an electric conductivity as possible. In the present invention, silver or a silver alloy is used. Silver, resistivity, 1.59 × 10 over ^{6 (Ω} · c
m), which is most preferably used because it has the best electrical conductivity among all materials and the thin film has excellent visible light transmittance. However, silver has a problem that it lacks stability when formed into a thin film and is susceptible to sulfidation and chlorination.
Therefore, in order to increase the stability, an alloy of silver and copper, an alloy of silver and palladium, an alloy of silver and platinum, or the like may be used instead of silver.

The material of the metal layer (c) in the present invention is preferably a material which has excellent environmental resistance and is as transparent as possible in a thin film state. Here, "excellent in environmental resistance" means that silver aggregation does not occur by an evaluation method by a film bonding and a high-temperature and high-humidity treatment described later. In addition, “excellent in transparency” means that the reduction rate of the luminous transmittance of the basic configuration of the transparent conductive thin film layer by forming the metal layer is 30% or less. An example of a material used for the metal layer is a metal excluding silver belonging to Groups 4 to 12 of the periodic table. Here, elements belonging to Groups 4 to 6, particularly titanium, zirconium, vanadium, tantalum, molybdenum, tungsten, and niobium are particularly preferably used.

The thickness of the metal layer is determined in consideration of the corrosion resistance to chloride ions and the transparency of the entire transparent conductive thin film layer according to the application. A thicker metal layer increases the corrosion resistance to chloride ions but decreases the permeability. Regarding the transmittance reduction rate, the luminous transmittance reduction rate is
It is preferably 40% or less. For this reason, the thickness of the metal layer varies depending on the material, but is typically 0.2 to 20 n.
m. Preferably, it is 0.3 to 10 nm. Here, when the thickness is about 2 nm or less, it corresponds to only the thickness of several atomic layers, it is considered that a dense thin film is not formed and atoms are attached in an island shape. In this case, it may be treated quantitatively depending on the element composition of the metal layer. The rate of decrease in luminous transmittance refers to the luminous transmittance of the transparent conductive thin film film having the metal layer (c) formed thereon as T1, and the luminous transmittance of the transparent conductive thin film film having no metal layer (c) formed thereon. (T2−T1) / T1 × 100 when the transmittance is defined as T2.

In the present invention, when a metal layer is provided on the outermost surface, the elemental composition of the main metal on the outermost surface is 3%.
What is necessary is just -99% (atomic ratio). Further, the outermost surface of a metal thin film is easily oxidized in the atmosphere, and usually, in most cases, an oxide thin film of the metal layer is automatically formed on the outermost surface. In this case, the metal layer
It is more stable because it is more stable and has higher environmental resistance. In addition, metal oxides are generally more permeable than non-oxidized, and are therefore more effective in terms of permeability. Of course, when forming this metal layer, the metal oxide layer may be intentionally formed by introducing oxygen gas or using an oxide member.

The high refractive index thin film layer and the metal thin film layer may be formed by a conventionally known method such as a vacuum evaporation method, an ion plating method, and a sputtering method. For forming the metal thin film layer, a vacuum evaporation method or a sputtering method is suitably used. In the vacuum evaporation method, a metal thin film can be easily formed by using a desired metal as an evaporation source and performing heating evaporation by resistance heating, electron beam heating, or the like. When a sputtering method is used, a desired metal material is used as a target, an inert gas such as argon or neon is used as a sputtering gas, and a metal thin film is formed using a DC sputtering method or a high-frequency sputtering method. Can be. In order to increase the deposition rate, a DC magnetron sputtering method or a high-frequency magnetron sputtering method is often used.

For the formation of the transparent conductive thin film layer, an ion plating method or a reactive sputtering method is suitably used. In the ion plating method, a desired metal or sintered body is subjected to vacuum deposition by resistance heating, electron beam heating or the like in a reactive gas plasma. In the reactive sputtering method, a desired metal or a sintered body is used as a target, and sputtering is performed using an inert gas such as argon or neon as a reactive sputtering gas. For example, I
In the case of forming a TO thin film, DC magnetron sputtering is performed in an oxygen gas using an oxide of indium and tin as a sputtering target. An adhesive is usually used for bonding the transparent support base and the film. The adhesive used in the present invention is preferably as transparent as possible. Specific examples of usable adhesives include acrylic adhesives, silicone adhesives, urethane adhesives, polyvinyl butyral adhesives (PVB),
Ethylene-vinyl acetate adhesive (EVA) and the like. Above all, acrylic pressure-sensitive adhesives are particularly preferably used because of their excellent transparency and heat resistance.

The form of the pressure-sensitive adhesive is roughly classified into a sheet-like material and a liquid-like material. The sheet-like pressure-sensitive adhesive is usually of a pressure-sensitive type, and after laminating the pressure-sensitive adhesive on one member to be pasted, the other member is further laminated to bond the two members together. The liquid adhesive is cured by leaving it at room temperature or heating after application and bonding. Examples of the method of applying the liquid adhesive include a bar coating method, a reverse coating method, a gravure coating method, and a roll coating method. It is selected in consideration of the type of material, viscosity, application amount, etc.

The thickness of the pressure-sensitive adhesive layer is not particularly limited.
It is 5 to 50 μm, preferably 1 to 30 μm. After bonding using an adhesive, pressurize and heat to remove the bubbles that entered during the bonding and dissolve them in the adhesive, and further improve the adhesion between the members. Curing is preferably performed under conditions. At this time, the pressure condition is generally about 0.001 to 2 MPa, and the heating condition is generally room temperature or higher and 80 ° C. or lower, depending on the heat resistance of each member. In the present invention, there is no particular limitation on the method of attaching the optical film to the transparent support substrate. Normally, an adhesive is stuck to the optical film, and the one covered with a release film is prepared in advance in a roll state, and the release film is peeled off while feeding the polymer molded film from the roll, It is pasted on a transparent support substrate and pasted while being held down by a roll. The same applies to a case where the film is laminated on the laminated film.

The optical filter having the ability to block electromagnetic waves is
Usually, it has an electrode for taking out a current from the transparent conductive thin film to the outside. The electrode shape is often formed on the frame at the outer peripheral portion in order to efficiently extract current from the largest possible area. Since the transparent conductive thin film has poor environmental resistance and is not preferably used bare, it is generally used as an electrode by covering the surface of the transparent conductive thin film with a conductive material. As a method for forming the electrodes, usually, a conductive paint is applied, printed, or a conductive tape is attached. The layer structure and the state of each layer of the optical filter produced by the above method can be examined by using a cross-sectional optical microscope measurement, a scanning electron microscope (SEM) measurement, and a transmission electron microscope measurement (TEM). The surface atomic composition of the thin film layer of the transparent conductive thin film used is determined by Auger electron spectroscopy (AES), X-ray fluorescence (XRF), X-ray microanalysis (XMA), charged particle excited X-ray analysis Law (R
BS), X-ray photoelectron spectroscopy (XPS), vacuum ultraviolet photoelectron spectroscopy (UPS), infrared absorption spectroscopy (IR), Raman spectroscopy, secondary ion mass spectroscopy (SIMS), low energy ion scattering spectroscopy (ISS). Further, the atomic composition and the film thickness in the film can be examined by performing Auger electron spectroscopy (AES) or secondary ion mass spectrometry (SIMS) in the depth direction.

When an anti-reflection film or the like is attached on the transparent conductive thin film, after peeling it off,
What is necessary is just to investigate by the above method. In addition, the environmental resistance of the optical filter, in the environment where the degree of cleanness is controlled, perform film bonding, and then perform high temperature and high humidity processing,
It can be examined by counting the number of occurrences of silver aggregation with the naked eye and determining the frequency of occurrence of silver aggregation. Cleanness is
There is no particular designation as long as it is controlled at a certain width. Usually, the class is about 100 to 10,000. Further, there is no particular designation for the temperature at which the high-temperature and high-humidity treatment is performed. Normally, temperature 4
The treatment is performed at a temperature of 0 to 120 ° C and a humidity of 50 to 99%.

[0035]

Next, the present invention will be described in detail with reference to examples.

Example 1 A polyethylene terephthalate film (thickness: 75 μm) was used as a transparent substrate (A), and one of its main surfaces was composed of an oxide of indium and tin using a DC magnetron sputtering method. The thin film layer (a), the silver thin film layer (b), and the titanium layer (c) are A / a
[Thickness 40 nm] / b [Thickness 15 nm] / a [Thickness 80]
nm] / b [thickness 20 nm] / a [thickness 80 nm] / b
[Thickness 15 nm] / a [Thickness 40 nm] / b [Thickness 15
nm] / a [thickness of 40 nm] / c [thickness of 1 nm] to form a transparent conductive thin film. The thin film layer made of an oxide of indium and tin constitutes a transparent high refractive index thin film layer, the silver thin film layer constitutes a metal thin film layer, and the titanium layer constitutes a metal layer. In forming a thin film layer composed of an oxide of indium and tin, as a target, an indium oxide / tin oxide sintered body [In ₂ O ₃ : SnO ₂ = 90: 10] was used.
(Weight ratio)], and an argon / oxygen mixed gas (total pressure 266 mPa, oxygen partial pressure 5 mPa) was used as a sputtering gas. Further, silver was used as a target for forming the silver thin film layer, and argon gas (total pressure 266) was used as a sputtering gas.
mPa) was used. In forming the titanium layer, titanium was used as a target, and argon gas (total pressure of 266 mPa) was used as a sputtering gas. Thus, a transparent conductive thin film (C) was produced.

Next, a transparent conductive thin film (C) is placed on one main surface of the transparent support substrate (B), and the transparent substrate (A) is
The substrates were bonded via an adhesive so as to be on the transparent support substrate side. The surface pressure at the time of bonding was 0.3 MPa. Further, an anti-reflection film (D) [thickness of 100 μm] was adhered to the other main surface of the transparent support substrate using an adhesive. The surface pressure at the time of bonding was 0.3 MPa.
Further, an antireflection film (D) [thickness of 100 μm] is adhered on the laminated transparent conductive thin film (C) via an adhesive so that the outer periphery of the transparent conductive thin film is exposed. I combined. The surface pressure at the time of bonding was 0.3 MPa.

The bonding of each film is performed with a cleanness of 1.
The test was performed in an environment of 000 to 5000. A silver paint was printed on the exposed transparent conductive thin film using a screen printing method. As described above, an optical filter was prepared. The luminous transmittance of the produced optical filter was measured [The total light transmittance was measured using a spectrophotometer U-3400 manufactured by Hitachi, Ltd., and the luminous transmittance was determined.

Further, the optical filter was placed in an environment of a temperature of 60 ° C. and a humidity of 90% for 24 hours, and thereafter, the frequency of occurrence of silver aggregation defects was examined. (Example 2) A zirconium layer [thickness 1 nm] was formed using zirconium instead of the titanium layer (c), and a transparent conductive thin film (C) was produced. . (Example 3) The same procedure as in Example 1 was carried out except that a hafnium layer [thickness 1 nm] was formed using hafnium instead of the titanium layer (c), and a transparent conductive thin film (C) was produced. . (Example 4) The same operation as in Example 1 was performed except that a vanadium layer [thickness 1 nm] was formed using vanadium instead of the titanium layer (c), and a transparent conductive thin film (C) was produced. .

(Example 5) Instead of the titanium layer (c),
The procedure was performed in the same manner as in Example 1 except that a niobium layer [thickness 1 nm] was formed using niobium, and a transparent conductive thin film (C) was produced. (Example 6) The same procedure as in Example 1 was carried out except that a tantalum layer [thickness 1 nm] was formed using tantalum instead of the titanium layer (c) to produce a transparent conductive thin film (C). . (Example 7) In the same manner as in Example 1 except that a chromium layer [thickness 1 nm] was formed using chromium instead of the titanium layer (c), and a transparent conductive thin film (C) was produced. . (Example 8) The same procedure as in Example 1 was carried out except that a molybdenum layer [1 nm thick] was formed using molybdenum instead of the titanium layer (c), and a transparent conductive thin film (C) was produced. . (Example 9) The same procedure as in Example 1 was carried out except that a tungsten layer [thickness 1 nm] was formed using tungsten instead of the titanium layer (c), and a transparent conductive thin film (C) was produced. .

Example 10 The same as Example 1 except that a manganese layer [1 nm thick] was formed using manganese instead of the titanium layer (c), and a transparent conductive thin film (C) was produced. It was carried out. (Example 11) The same procedure as in Example 1 was carried out except that a palladium layer [thickness 1 nm] was formed using palladium instead of the titanium layer (c), and a transparent conductive thin film (C) was produced. . (Example 12) The same procedure as in Example 1 was carried out except that a platinum layer [thickness 1 nm] was formed using platinum instead of the titanium layer (c), and a transparent conductive thin film (C) was produced. . (Example 13) In the same manner as in Example 1 except that a copper layer [thickness 1 nm] was formed using copper instead of the titanium layer (c), and a transparent conductive thin film (C) was produced. . (Example 14) In the same manner as in Example 1 except that a gold layer [thickness 1 nm] was formed using gold instead of the titanium layer (c), and a transparent conductive thin film (C) was produced. .

Example 15 The same as Example 1 except that a zinc layer [1 nm thick] was formed using zinc instead of the titanium layer (c), and a transparent conductive thin film (C) was produced. It was carried out. (Example 16) A thin film layer (a), a silver thin film layer (b), and a titanium layer (c) composed of an oxide of indium and tin were formed of A / a
[Thickness 40 nm] / b [Thickness 15 nm] / a [Thickness 80]
nm] / b [thickness 20 nm] / a [thickness 80 nm] / b
[Thickness 15 nm] / a [Thickness 40 nm] / b [Thickness 15
nm] / c [thickness 1 nm] / d [thickness 40 nm] were stacked in this order to form a transparent conductive film, except that a transparent conductive film was formed. Example 17 Example 1 was repeated except that a zirconium layer [thickness 1 nm] was formed using zirconium instead of the titanium layer (c) to produce a transparent conductive thin film (c).
Was performed in the same manner as described above. (Example 18) The same operation as in Example 1 was carried out except that a hafnium layer [thickness 1 nm] was formed using hafnium instead of the titanium layer (c), and a transparent conductive thin film (c) was produced. . (Example 19) In the same manner as in Example 1 except that a vanadium layer [thickness 1 nm] was formed using vanadium instead of the titanium layer (c), and a transparent conductive thin film (c) was produced. .

Example 20 A niobium layer [thickness 1 nm] was formed using niobium instead of the titanium layer (c).
The procedure was performed in the same manner as in Example 1 except that the transparent conductive thin film (c) was produced. (Example 21) In the same manner as in Example 1 except that a tantalum layer [thickness 1 nm] was formed using tantalum instead of the titanium layer (c), and a transparent conductive thin film (c) was produced. . (Example 22) In the same manner as in Example 1 except that a chromium layer [thickness 1 nm] was formed using chromium instead of the titanium layer (c), and a transparent conductive thin film (c) was produced. . (Example 23) The same procedure as in Example 1 was carried out except that a molybdenum layer [thickness 1 nm] was formed using molybdenum instead of the titanium layer (c), and a transparent conductive thin film layer (c) was produced. . (Example 24) The same procedure as in Example 1 was carried out except that a tungsten layer [1 nm] was formed using tungsten instead of the titanium layer (c) to produce a transparent conductive thin film (c).

Example 25 The procedure of Example 1 was repeated, except that a manganese layer [1 nm thick] was formed using manganese instead of the titanium layer (c), and a transparent conductive thin film (c) was produced. It was carried out. (Example 26) In the same manner as in Example 1 except that a palladium layer [thickness 1 nm] was formed using palladium instead of the titanium layer (c), and a transparent conductive thin film (c) was produced. . (Example 27) The same operation as in Example 1 was carried out except that a platinum layer [thickness 1 nm] was formed using platinum instead of titanium (c), and a transparent conductive thin film (c) was produced. (Example 28) In the same manner as in Example 1 except that a copper layer [thickness 1 nm] was formed using copper instead of the titanium layer (c), and a transparent conductive thin film (c) was produced. . (Example 29) In the same manner as in Example 1 except that a gold layer [thickness 1 nm] was formed using gold instead of the titanium layer (c), and a transparent conductive thin film (c) was produced. . (Example 30) The same procedure as in Example 1 was carried out except that a zinc layer [thickness 1 nm] was formed using zinc instead of the titanium layer (c) to prepare a transparent conductive thin film (c). .

(Comparative Example) The same operation as in Example 1 was carried out except that a transparent conductive thin film (C) was formed without forming the titanium layer (c). The luminous transmittance of the produced optical filter was 58%. Table 1 shows the above results.

[0046]

[Table 1]

[0047]

As is clear from Table 1, in all of the examples, the corrosion resistance of the optical filter to chloride ions without significant decrease in the luminous transmittance was determined by the metal layer (c) in the transparent conductive thin film. It can be seen that the formation of ()) has greatly improved.

[Brief description of the drawings]

FIG.

FIG.

FIG.

FIG. 4 is a cross-sectional view showing an example of a transparent conductive thin film used for an optical filter for a plasma display.

FIG. 5 is a sectional view showing an example of an optical filter for a plasma display.

FIG. 6 is a sectional view showing an example of an optical filter for a plasma display (electrode side).

[Explanation of symbols]

 Reference Signs List 10 transparent substrate (A) 20 transparent high refractive index thin film layer (a) 30 metal thin film layer (b) 40 metal layer (c) 50 transparent support substrate (B) 60 transparent conductive thin film (C) 70 antireflection film ( D) 80 electrodes (F)

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Shin Fukuda 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture F-term (reference) 2H048 FA05 FA09 FA13 FA24 4F100 AA17C AA25C AA28C AB01D AB12D AB17D AB24B AB25D AB31B AB33B AK42A AR00A BA04 BA07 BA10A BA10D GB56 JG01 JM02C JN01 JN01A JN01C JN18C 5G307 FA02 FB01 FB02 FC02 FC09 FC10

Claims (8)

[Claims] 1. An optical filter having a transparent conductive thin film layer, wherein a transparent high refractive index thin film layer (a) is provided on at least one principal surface of a transparent substrate (A). , A metal thin film layer (b) made of silver or an alloy containing silver, and a metal layer (c) containing at least one metal other than silver in Groups 4 to 12 of the periodic table of elements. / B / a / c, A / b / c / a, A / a
/ B / a / c, A / a / b / c / a, A / b / a / b /
a / c, A / b / a / b / c / a, A / a / b / a / b
/ A / c, A / a / b / a / b / c / a, A / b / a /
b / a / b / a / c, A / b / a / b / a / b / c /
a, A / a / b / a / b / a / b / a / c, A / a / b
/ A / b / a / b / c / a, A / b / a / b / a / b /
a / b / a / c, A / b / a / b / a / b / a / b / c
/ A, A / a / b / a / b / a / b / a / b / a / c,
A / a / b / a / b / a / b / a / b / c / a, A / a
/ B / a / b / a / b / a / b / a / b / a / c, A /
An optical filter which is laminated on any one of a / b / a / b / a / b / a / b / a / b / c / a. 2. The metal layer (c) is provided with 4 to 7 of the periodic table.
The optical filter according to claim 1, further comprising a group III metal. 3. The optical filter according to claim 1, wherein the metal layer (c) contains at least one metal selected from copper, palladium, platinum and gold. 4. The elemental composition of the metal of the metal layer (c) is 3.
The optical filter according to any one of claims 1 to 3, wherein the optical filter is at least 0% (atomic ratio) and at most 99.9% (atomic ratio). 5. The metal layer (c) has a thickness of 0.3 nm or more and 10 nm or less.
The optical filter according to any one of the above. 6. The optical filter according to claim 1, wherein the transparent high refractive index thin film layer (a) is made of at least one selected from indium oxide, tin oxide and zinc oxide. . 7. The optical filter according to claim 1, wherein the cross-sectional structure is an antireflection layer / film substrate / adhesive layer / transparent conductive thin film layer / film substrate / adhesive layer. / Transparent support substrate, antireflection layer / film substrate / adhesive layer / transparent conductive thin film layer / film substrate / adhesive layer / transparent support substrate / antireflection layer, antireflection layer / film substrate / adhesive layer / transparent conductive Thin film layer / film substrate / adhesive layer / transparent support substrate / adhesive layer / film substrate / anti-reflection layer, anti-reflection layer /
Film substrate / adhesive layer / film substrate / transparent conductive thin film layer / adhesive layer / transparent support substrate, antireflection layer / film substrate /
Adhesive layer / Film substrate / Transparent conductive thin film layer / Adhesive layer / Transparent support substrate / Anti-reflective layer, Anti-reflective layer / Film substrate / Adhesive layer / Film substrate / Transparent conductive thin film layer / Adhesive layer / Transparent Support substrate / Adhesive layer / Film substrate / Anti-reflective layer, Anti-reflective layer / Film substrate / Transparent conductive thin film layer / Adhesive layer / Transparent support substrate, Anti-reflective layer / Film substrate / Transparent conductive thin film layer /
Adhesive layer / transparent support substrate / anti-reflection layer, anti-reflection layer / film substrate / transparent conductive thin film layer / adhesive layer / transparent support substrate / adhesive layer / film substrate / anti-reflection layer Optical filter, 8. An optical filter for a plasma display according to claim 1.