JP2007286165A - Optical filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical filter which does not deteriorate an adhesive material layer to contact with an oxide involving zinc when using a conductive stacked body containing the oxide of zinc. <P>SOLUTION: By forming a thin film layer containing at least one of periodical table fifth group or sixth group elements between the conductive stacked body in which a high-refractive index thin film layer is stacked on a metal thin film layer containing silver or silver alloy and a layer containing the oxide of zinc further is disposed thereon, and the adhesive material layer, the optical filter which suppresses the deterioration of the adhesive material layer and has high reliability with respect to environmental resistance can be provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical filter having excellent optical stability.

  Optoelectronics components and equipment are making significant progress every day. In particular, displays for displaying images have been rapidly developed for computer monitor devices in addition to conventional television receivers. In addition to commercial use, the number of popular homes has increased rapidly, and the places of use have also diversified. Along with these developments, market demands for display enlargement, thinning, and high image quality are increasing.

  As displays satisfying the above requirements, so-called flat panel displays such as plasma display panels, liquid crystal displays, electroluminescence displays, rear projections, etc. have undergone remarkable development. Among them, the plasma display panel is a centerpiece as a large-sized, high-quality and thin display, and the plasma display panel market is expected to grow.

  Due to the light emission principle of plasma display panels, strong electromagnetic waves and near infrared rays are emitted to the outside. In order to use a plasma display panel, it is essential to shield strong electromagnetic waves and near infrared rays. Conventionally, in order to shield the strong electromagnetic wave, a low-resistance and transparent optical filter having an electromagnetic wave shielding function has been used (for example, see Patent Document 1). As the optical filter, an optical filter using a transparent conductive thin film, an optical filter using a conductive mesh having higher electromagnetic wave shielding ability, and the like are used. The electromagnetic wave shielding ability tends to be better as the surface resistivity of the optical filter is lower.

  In particular, an optical filter using a transparent conductive thin film is very preferably used because it is inexpensive and can simultaneously cut electromagnetic waves and near infrared rays emitted from a plasma display panel. A transparent conductive thin film is a thin film having conductivity despite being transparent. A typical example is a thin film made of an oxide of indium and tin (ITO), and its application is wide. However, since indium is a very rare substance, its price is unstable. Therefore, development of a transparent conductive thin film using a material replacing indium is desired.

Conventionally, materials containing zinc oxide are expected as substitutes for indium and ITO, and some of them are already used. However, since zinc oxide is an amphoteric oxide, it is highly reactive and tends to interact (react) with many substances. Therefore, in an optical filter using zinc oxide, a reaction occurs between the zinc oxide layer and the adhesive layer particularly at high temperatures and in a high temperature and high humidity environment, resulting in a decrease in light transmittance or discoloration of the optical filter. It sometimes occurred.
Japanese Patent No. 3004222

  Therefore, the problem to be solved by the present invention is to provide an optical filter excellent in reliability, particularly when there is little change in the properties of the adhesive layer when a transparent conductive thin film containing zinc oxide is used. is there.

  In order to solve the problems of the present invention, the present inventors have intensively studied. As a result, in order to provide an optical filter having excellent reliability even when zinc oxide is used, a periodic table group 5 or 6 is formed between members formed in contact with a transparent conductive thin film containing zinc oxide. It has been found that by forming a thin film layer containing at least one group element, it is possible to provide an optical filter that suppresses changes in the properties of the material formed thereon, and the present invention has been completed.

That is, the first invention is
(1) On at least the transparent substrate (A), the high refractive index thin film layer (a) and the metal thin film layer (b) containing silver or a silver alloy are 1 with (a) / (b) as the structural unit. A high-refractive-index thin film layer (c) formed of at least a unit and further containing zinc oxide is laminated thereon, and the fifth index of the periodic table is further formed on the high-refractive-index thin film layer (c) containing the zinc oxide. A conductive laminate in which a thin film layer (d) containing at least one group or group 6 element is formed, and an adhesive formed on the thin film layer (d) so as to be in contact with the thin film layer (d) It is an optical filter characterized by having a material layer (B).
(2) It is a preferred embodiment that the optical filter is formed from 1 unit to 7 units with (a) / (b) as structural units.
(3) It is preferable that the thin film layer (d) is an optical filter containing at least one element selected from tantalum or niobium in terms of prevention of alteration of the adhesive layer, optical characteristics and electrical characteristics of the optical filter. It is an aspect.

The second invention is
(4) The above-mentioned optical filter intended for use for a plasma display panel.

  Since the optical filter of the present invention can suppress deterioration of the adhesive layer of a member to be bonded to a conductive laminate using a material containing zinc oxide, it can be used without limiting the material used in combination. It is possible to make an optical filter that is possible. In other words, high durability, high image quality, and productivity that make the most of each member's functions are achieved through the synergistic effect of the functions of the members used together, along with the high durability of the conductive laminate and the stable price of the members. An excellent optical filter can be provided.

  The optical filter in the present invention is a thin film layer containing at least a Group 5 or Group 6 element on a conductive laminate using a material containing a zinc oxide formed on a transparent substrate (A). (D), and the adhesive layer (B) is formed on the thin film layer (d).

  The transparent substrate (A) constituting the optical filter of the present invention is preferably a film and a plate, is excellent in transparency, and has a sufficient mechanical strength depending on the application. The term “excellent transparency” as used herein means that the visible light transmittance is 40% or more in the thickness in a used state (measurement method: JIS R3106). For example, a polymer film, a polymer plate, or a glass plate is preferably used as the transparent substrate (A). In the present invention, a known transparent substrate as described above can be used without limitation.

  In the conductive laminate constituting the optical filter of the present invention, the high-refractive-index thin film layer (a) and the metal thin film layer (b) made of silver or a silver alloy are 1 unit with (a) / (b) as a structural unit. A high refractive index thin film layer (c) containing zinc oxide and a thin film layer (d) containing at least one group 5 or 6 element of the periodic table are formed thereon. It is characterized by being a conductive laminate.

  Examples of materials that can be suitably used for the high refractive index thin film layer (a) in the optical filter of the present invention include oxides of indium and tin (abbreviation: ITO), oxides of cadmium and tin (abbreviation: CTO). ), Zinc and tin oxide, zinc and gallium oxide, indium and cerium oxide, aluminum oxide, zinc oxide, zinc and aluminum oxide (abbreviation: AZO), magnesium oxide, thorium oxide, oxidation Examples thereof include tin, lanthanum oxide, silicon oxide, indium oxide, niobium oxide, antimony oxide, zirconium oxide, cesium oxide, titanium oxide, and bismuth oxide. A transparent high refractive index sulfide may be used. Specific examples include zinc sulfide, cadmium sulfide, antimony sulfide and the like. As materials for the high refractive index thin film layer, ITO, titanium oxide, zinc oxide, and AZO are particularly preferable. ITO and AZO are preferably used because they have electrical conductivity and have a high refractive index of about 2.0 in the visible light region, and hardly absorb light in the visible light region. Moreover, by using a material containing zinc oxide, it becomes possible to supply an optical filter that is more stable in terms of cost and durability than a conductive laminate using ITO. As long as the high refractive index thin film layer contains at least the above-described conductive material, it may be a composite with other materials for reasons such as film forming property, productivity, and durability, or other materials may be added. It does not matter.

  The high refractive index thin film layer (a) used in the optical filter of the present invention does not need to be made of the same material for all layers, and each high refractive index thin film layer (a) is completely different or partly different. A plurality of materials, such as materials, may be used simultaneously. The high refractive index thin film layer (a) may be the same material as the high refractive index thin film layer (c) containing zinc oxide described later.

  The metal thin film layer (b) preferably contains silver or a silver alloy. As the silver alloy, an alloy such as silver and gold, silver and copper, silver and palladium, or silver and platinum may be used in order to increase stability. Similarly to the high refractive index thin film layer (a), as long as it contains silver or a silver alloy, it may be a composite with other substances or other substances may be added. Examples of other substances include niobium, tin, indium, bismuth, and titanium, but known dopant materials can be used.

  The high-refractive-index thin film layer (c) containing zinc oxide may be a complex with other substances or may be added with other substances as long as it contains at least zinc oxide which is a conductive substance. Absent. Examples of other substances include, but are not limited to, gallium, aluminum, tin, indium, magnesium hafnium, titanium, and zirconium.

  As long as the element used for the thin film layer (d) is an element of Group 5 or Group 6 of the periodic table, it can be used without particular limitation in accordance with the optical characteristics and electrical characteristics of the obtained optical filter. A metal, oxide, nitride, or a mixture thereof can be used for the thin film layer (d) as long as it contains at least one element selected from Group 5 or Group 6 of the periodic table. . In particular, a material containing tantalum or niobium is preferable.

  The elements of Group 5 or Group 6 of the periodic table used for the thin film layer (d) of the present invention are stable elements having high electron affinity and excellent corrosion resistance. Therefore, by forming a layer containing an element selected from Group 5 or Group 6 of the periodic table on the conductive laminate, an adhesive layer of a member bonded with a highly reactive zinc oxide ( It becomes possible to suppress the change of B). For this reason, it is possible to select an optimal member from among members having excellent bonding functions without considering the type of adhesive.

  The high refractive index thin film layer (a), the metal thin film layer (b), the high refractive index thin film layer (c) containing zinc oxide, and the thin film layer (d) can be formed by sputtering, vacuum deposition, ion In addition to vacuum film forming methods such as a plating method and an ion beam assist method, any known method can be adopted. Among these, a vacuum film forming method, particularly a sputtering method can be preferably used. A layer may be formed using a plurality of methods.

  (A) (b) (c) (d) You may have a functional layer which has various functions between each layer and the surface. Examples of the functional layer include an adhesion improving layer, a gas barrier layer, and a layer for improving environmental resistance.

  The number of layers and the film thickness of each layer of the conductive laminate are determined in accordance with the intended electrical characteristics and optical characteristics. As the number of layers of the conductive laminate, the larger the number of layers of the high refractive index thin film layer (a) and the metal thin film layer (b), the better from the viewpoint of the balance between conductivity and light transmittance, but the cost and quality In consideration of stability, the structural unit (a) / (b) is preferably 1 unit or more and 7 units or less. The total number of layers (a), (b) and (c) is preferably 11 or less, more preferably 9 or less.

  The film thickness of the thin film layer (d) is determined by the state of the element used, oxide, etc., but is preferably 1 nm to 20 nm.

  The optical filter of the present invention comprises a high refractive index thin film layer (a) containing at least a transparent substrate (A) / zinc oxide and a metal thin film layer (b) made of silver or a silver alloy. If the filter has a configuration of a conductive laminate / adhesive layer (B) formed with a plurality of layers having other functions, the optical filter of the present invention may have other functions. Examples of the layers include toning layers, conductive layers, adhesive layers, impact mitigation layers, electrode layers, antireflection layers, antiglare layers, antifouling layers, hard coat layers, anti-Newton ring layers, ultraviolet absorption layers, and the like. Can be mentioned. These layers may have a plurality of functions at the same time. The layer having other functions may be directly formed on the optical filter of the present invention, or a substrate having other functions may be laminated on the optical filter of the present invention.

  Examples of the toning layer include a layer containing a pigment. The dye can be used without being limited to a dye or a pigment as long as it can achieve a color tone according to the purpose. In the present invention, it is described as a pigment without distinction between a dye and a pigment. Specific examples of dyes and pigments include anthraquinone, phthalocyanine, methine, azomethine, oxazine, azo, styryl, coumarin, porphyrin, dibenzofuranone, diketopyrrolopyrrole, rhodamine, Examples include xanthene-based, pyromethene-based, squarylium-based, cyanine-based, oxonol-based compounds, and carbon black. In order to adjust the optical characteristics according to desired optical characteristics, a dye having absorption in the visible light region, near-infrared region, and ultraviolet region other than the dye may be used in combination. Moreover, it is not restricted to this, You may use together 2 or more types of pigment | dyes simultaneously. Further, two or more toning layers may be simultaneously provided, or two or more layers that can be regarded as toning layers may be present at the same time.

  Any known technique can be used as the method of forming the toning layer. Specific examples include (1) a method of incorporating a dye into a transparent substrate such as a polymer molded body, (2) applying to a transparent substrate surface, and (3) a method of incorporating it into an adhesive. Any known technique may be used as a method for containing the dye as long as the dye is uniformly distributed.

  (1) Specific examples of the method of incorporating a dye into a polymer molded body include conditions such as processing temperature depending on the type of base resin mixed with the dye, but usually the dye is a base resin powder or pellet. And a method of heating and melting from 150 ° C. to 350 ° C. in consideration of the melting temperature of the resin, and preferably kneading and molding to produce a plastic sheet and plastic particles. An additive such as a plasticizer may be added for the purpose of facilitating molding.

  There is a casting method as another method. In the casting method, a dye is added to and dissolved in a resin solution in which a resin or resin monomer is dissolved in an organic solvent, and a plasticizer, a polymerization initiator, an antioxidant, etc. are added as necessary, and the required surface state The polymer molded body can be obtained by pouring into a metal mold having a solvent and volatilizing, drying, or polymerizing, solvent volatilizing and drying. The addition amount of the dye varies depending on the absorption coefficient of the dye, the thickness of the polymer molded article, and the desired transmission characteristics, but is usually 1 ppm to 20 mass percent of the base resin molded article.

  Specific examples of the method of applying the pigment (2) to the polymer molded body or the glass surface are shown below. A paint prepared by dissolving a dye in a binder resin and an organic solvent, or a finely pulverized dye (particle size 50 nm to 500 nm) dispersed in an uncolored acrylic emulsion paint to obtain an acrylic emulsion aqueous paint. Examples thereof include a method of applying and drying a product by a conventionally known coating method such as a bar coater, a blade coater, a spin coater, a reverse coater, a die coater, or a spray. The concentration of the dye varies depending on the absorption coefficient of the dye, the thickness of the coating, and the target optical characteristics, but is 1 ppm by mass to 30% by mass with respect to the binder resin. An antioxidant or the like may be added to the paint. A protective layer may be provided for the purpose of protecting the coating surface.

  (3) A method of incorporating a pigment into the adhesive is specifically exemplified. Adhesive materials include acrylic resin, silicone resin, urethane resin, polyvinyl butyral resin, ethylene-vinyl acetate resin, polyvinyl ether resin, saturated amorphous polyester, melamine resin, etc. Is mentioned. A pigment is added to these adhesives to obtain a pigmented adhesive. The addition amount of the dye varies depending on the absorption coefficient of the dye, the thickness of the adhesive, and the desired optical characteristics, but is usually 1 ppm to 30 mass percent of the base adhesive.

  Examples of the method for forming an adhesive include a method in which an adhesive is directly applied to a substrate, or a method in which one release film of an adhesive sandwiched between release films is peeled off and bonded to a substrate. . Generally, the adhesive is applied by a bar coating method, a reverse coating method, a gravure coating method, a roll coating method or the like, but is not limited thereto. The thickness of the adhesive is not particularly limited, but is 0.5 μm to 50 μm, preferably 1 μm to 30 μm.

  The adhesive can be used for various types of bonding such as a film and a film and a film and a glass, and is one of the preferred forms as a method of containing a pigment.

  Some dyes have poor light resistance, and when used as an optical filter, deterioration due to light of the device itself, ultraviolet light of external light, or visible light may become a problem. In this case, the deterioration of the dye is reduced by using in combination with a member containing an ultraviolet absorber, a member (layer) that does not transmit ultraviolet light, a member that includes a dye that absorbs light of a wavelength that causes the dye to change, or a member that does not transmit the light. can do. These members are preferably used on the side on which ultraviolet rays or visible rays are incident rather than the layer containing the dye. In addition, a known light blocking technique can be used.

  The same applies to a combination of light, heat and humidity, and a combination of these. When the dye is altered, the transmission characteristics of the optical filter itself may change, and the color tone may change. Moreover, the near-infrared cutting ability may change. Therefore, a dye having high temperature resistance and wet heat resistance can be used more preferably. Furthermore, when using a pigment | dye, in order to disperse | distribute it in a medium or a coating film, since the solubility and dispersibility to a solvent are also important, the pigment | dye with good solubility and dispersibility can be used preferably.

The optical filter of the present invention can be preferably used for a plasma display panel. An example of a preferred form when used in a plasma display panel is as follows:
(I) The structure containing a pigment | dye in the at least 1 or more member which comprises an optical filter (ii) The structure containing a toning layer is mentioned. However, any conventionally known method can be applied to the optical filter of the present invention used for a plasma display panel, and is not limited to the above (i) and (ii).

  Specifically, the functions imparted to the members constituting the optical filter for the plasma display panel of the present invention include hard coat properties, antireflection properties, antiglare properties, antistatic properties, antifouling properties, gas barrier properties, and ultraviolet cut properties. At least one or more of known functions such as a near infrared ray cutting ability, a color tone adjustment function, an anti-Newton ring layer, and a conductive mesh flattening function to be described later may be mentioned, but the function to be given is limited to this. Is not to be done. The function and configuration to be given to the optical filter are appropriately designed according to the purpose. In particular, it is preferable that the layer having the ability to cut ultraviolet rays is disposed on the human side, not on the side close to the display of the optical filter. Moreover, as long as it has the said function, it can take arbitrary forms, such as a coating film, a film, an adhesive material layer, and its composite body, As a formation method, it is not specifically limited, Well-known Any technology can be used. Two or more layers having a function may be formed, or one layer may have a plurality of functions. Moreover, you may provide said function including the function to adjust the color tone as a display to the adhesive material layer used for bonding of each layer.

  The optical filter for a plasma display panel of the present invention preferably has at least an electromagnetic shielding function and a near infrared shielding function. This is because a display device such as a plasma display panel may generate leakage electromagnetic waves or near infrared rays due to its structure and operation principle, and these must be shielded.

  Usually, in order to shield electromagnetic waves, the surface of a display is often covered with a highly conductive material. The conductive material absorbs an electromagnetic wave and releases it as an electric charge, thereby exhibiting an electromagnetic wave shielding ability. Electromagnetic waves can be shielded by providing a conductive layer on the optical filter for a plasma display panel.

  The conductivity necessary for shielding the electromagnetic wave of the plasma display panel depends on the required electromagnetic wave standard and the radiation intensity from the plasma display panel, but the surface resistivity of the conductive layer is preferably 10Ω / □ or less, more preferably. Is 3Ω / □. In the case of strict electromagnetic wave standards required for consumer use, it is preferably 1.5Ω / □ or less, and more preferably 1.0Ω / □ or less.

  In order to shield near infrared rays generated from the plasma display panel, it is preferable that the transmittance of the optical filter is 20% or less in the near infrared wavelength region having a wavelength of 800 to 1000 nm.

  The conductive laminate of the present invention is less expensive than the conductive mesh layer and has the property of reflecting near infrared rays by the free electrons of the metal constituting the metal thin film layer. It has the feature of having both. In the present invention, a conductive laminate is preferably used as the conductive layer.

  From the above, by disposing the optical filter for a plasma display panel of the present invention on the front surface of the plasma display panel, it is possible to provide a better image as a display in addition to shielding electromagnetic waves and cutting near infrared rays. .

The present invention will be specifically described with reference to examples. The present invention is not limited to the following examples.
[Example 1]
Using a polyethylene terephthalate (PET) film [manufactured by Teijin DuPont Co., Ltd., Tetron film, thickness: 75 μm] as a transparent substrate, using a direct current magnetron sputtering method on one side of the transparent substrate, zinc and tin Tantalum as the oxide layer, silver layer, thin film layer (d), PET / zinc and tin oxide layer [film thickness: 35 nm] / silver layer [film thickness: 10 nm] / zinc and tin oxide layer [ Film thickness: 90 nm] / silver layer [film thickness: 15 nm] / zinc and tin oxide layer [film thickness: 90 nm] / silver layer [film thickness: 10 nm] / zinc and tin oxide layer [film thickness: 35 nm ] / Tantalum [film thickness: 5 nm] in this order to form a conductive laminate. For forming the oxide layer of zinc and tin, a ZnSn target [manufactured by Bekaert, Zn: Sn = 95: 5 (weight ratio)] and a mixed gas of argon and oxygen gas as sputtering gas [total pressure: 266 mPa , Oxygen partial pressure: 133 mPa] was used. For forming the silver layer, silver was used as a target, and argon gas [total pressure: 266 mPa] was used as a sputtering gas. For the thin film layer (d), a tantalum target [manufactured by Kojundo Chemical Laboratory Co., Ltd.] and argon gas [total pressure: 266 mPa] as a sputtering gas were used. A protective film having an adhesive layer [thickness: 3 μm] is laminated on a polyethylene film [Mitsui Chemicals, Inc., thickness: 50 μm] on the thin film layer (d) of the conductive laminate formed as described above. It was.
A transparent base material in which a protective film is bonded to one side of a heat treated glass having a thickness of 3 mm via a transparent acrylic adhesive and a conductive laminate, so that the transparent base becomes the adhesive. Pasted together.
Further, the protective film bonded to the conductive laminate is peeled off, and an antireflection film [manufactured by Nippon Oil & Fats Co., Ltd., thickness: 105 μm] attached with a transparent adhesive is bonded onto the conductive laminate to optically A filter was produced.

[Example 2]
The laminated structure is PET / zinc and tin oxide layer [film thickness: 30 nm] / silver layer [film thickness: 8 nm] / zinc and tin oxide layer [film thickness: 80 nm] / silver layer [film thickness: 15 nm]. / Zinc and tin oxide layer [film thickness: 80 nm] / silver layer [film thickness: 15 nm] / zinc and tin oxide layer [film thickness: 80 nm] / silver layer [film thickness: 8 nm] / zinc and tin An optical filter was produced in the same manner as in Example 1 except that the conductive laminate was formed so that the oxide layer [film thickness: 30 nm] / tantalum [film thickness: 5 nm] was formed.

[Example 3]
An optical filter was produced in the same manner as in Example 1 except that niobium was used as the thin film layer (d) and a niobium target [manufactured by Nilaco Corporation] was used as the target.

[Example 4]
An optical filter was produced in the same manner as in Example 2 except that niobium was used as the thin film layer (d) and a niobium target [manufactured by Nilaco Corporation] was used as the target.

[Example 5]
Using a polyethylene terephthalate (PET) film [manufactured by Teijin DuPont Co., Ltd., Tetron film, thickness: 75 μm] as a transparent substrate, using a direct current magnetron sputtering method on one side of the transparent substrate, zinc and tin Tantalum as the oxide layer, silver layer, thin film layer (d), PET / zinc and tin oxide layer [film thickness: 35 nm] / silver layer [film thickness: 10 nm] / zinc and tin oxide layer [ Film thickness: 90 nm] / silver layer [film thickness: 15 nm] / zinc and tin oxide layer [film thickness: 90 nm] / silver layer [film thickness: 10 nm] / zinc and tin oxide layer [film thickness: 35 nm ] / Tantalum oxide [film thickness: 10 nm] in this order to form a conductive laminate. For forming the oxide layer of zinc and tin, a ZnSn target [manufactured by Bekaert, Zn: Sn = 95: 5 (weight ratio)] and a mixed gas of argon and oxygen gas as sputtering gas [total pressure: 266 mPa , Oxygen partial pressure: 133 mPa] was used. For forming the silver layer, silver was used as a target, and argon gas [total pressure: 266 mPa] was used as a sputtering gas. For the thin film layer (d), a tantalum target [manufactured by Kojundo Chemical Laboratory Co., Ltd.] and a mixed gas of argon and oxygen gas [total pressure: 266 mPa, oxygen partial pressure: 133 mPa] were used as the sputtering gas. A protective film having an adhesive layer [thickness: 3 μm] on a polyethylene film [Mitsui Chemicals, Inc., thickness: 50 μm] was bonded onto the conductive laminate formed as described above. The surface pressure at the time of bonding was 0.3 MPa.

[Example 6]
The laminated structure is PET / zinc and tin oxide layer [film thickness: 30 nm] / silver layer [film thickness: 8 nm] / zinc and tin oxide layer [film thickness: 80 nm] / silver layer [film thickness: 15 nm]. / Zinc and tin oxide layer [film thickness: 80 nm] / silver layer [film thickness: 15 nm] / zinc and tin oxide layer [film thickness: 80 nm] / silver layer [film thickness: 8 nm] / zinc and tin The oxide layer [film thickness: 30 nm] / tantalum oxide [film thickness: 10 nm] was prepared in the same manner as in Example 5 except that the conductive laminate was formed.

[Example 7]
It was produced in the same manner as in Example 5 except that niobium was used as the thin film layer (d), a niobium target [manufactured by Nilaco Corporation] was used as a target, and niobium oxide was formed instead of tantalum oxide.

[Example 8]
It was produced in the same manner as in Example 6 except that niobium was used as the thin film layer (d), a niobium target [manufactured by Nilaco Corporation] was used as a target, and niobium oxide was formed instead of tantalum oxide.

[Comparative Example 1]
PET / zinc and tin oxide layer [film thickness: 35 nm] / silver layer [film thickness: 10 nm] / zinc and tin oxide layer [film thickness: 90 nm] / silver layer [film thickness: 15 nm] / Zinc and tin oxide layer [film thickness: 90 nm] / silver layer [film thickness: 10 nm] / zinc and tin oxide layer [film thickness: 35 nm] and no thin film layer (d) was formed Other than this, the same production as in Example 1 was performed.

[Comparative Example 2]
PET / zinc and tin oxide layer [film thickness: 30 nm] / silver layer [film thickness: 8 nm] / zinc and tin oxide layer [film thickness: 80 nm] / silver layer [film thickness: 15 nm] / Zinc and tin oxide layer [film thickness: 80 nm] / silver layer [film thickness: 15 nm] / zinc and tin oxide layer [film thickness: 80 nm] / silver layer [film thickness: 8 nm] / zinc and tin The oxide layer [film thickness: 30 nm] was prepared in the same manner as in Example 2 except that the thin film layer (d) was not formed.
The produced optical filter was subjected to a high-temperature and high-humidity environmental test of 60 ° C. and 90% RH using a thermo-hygrostat [Enomoto Kasei Co., Ltd., FX2200]. The produced optical filter is held for 250 hours under these conditions, and the light transmittance of the optical filter after 250 hours is measured with a spectrophotometer [Measuring method: JIS R3106] (measuring instrument: spectrophotometer manufactured by Hitachi, Ltd.) , U-3400), and the light transmittance at wavelengths of 400 nm and 650 nm before the test. It is preferable to use the optical filter as little as possible before and after the environmental test.

  Table 1 shows the absolute value of the change in light transmittance before and after the environmental test. Note that the amount of change in light transmittance here is (light transmittance after environmental test at each wavelength position [%]) and (light transmittance before environmental test at each wavelength position [%]). It is a difference. As a result, the optical filter of the present invention in which the thin film layer (d) was formed had an absolute value of change in light transmittance that was smaller than that of the optical filter without the thin film layer (d), and suppressed deterioration.

[Example 9]
It was produced in the same manner as in Example 6 except that an antireflection (AR) film was bonded onto the conductive laminate using an adhesive containing a pigment.
When the adhesive containing the pigment is dispersed and dissolved in tetraazaporphyrin compound, anthraquinone compound, quinophthalone compound, and carbon black in a mixed solvent of ethyl acetate and toluene (ratio 50: 50% by mass), and dried, The pigment-containing diluent for the acrylic pressure-sensitive adhesive material was prepared so that the dye concentrations of 1000 (wt) ppm, 800 (wt) ppm, 300 (wt) ppm, and 4000 (wt) ppm, respectively. Next, an acrylic pressure-sensitive adhesive (a copolymer of butyl acrylate and acrylic acid (trade name, DB bond, manufactured by Diabond Kogyo Co., Ltd.)) and a dye-containing diluent are mixed at 80: 20% by mass, and the bar coater method is used. Was continuously coated on a release layer of a release film comprising a polyethylene terephthalate film and a silicone release layer, and dried. Thereafter, another release film was bonded to the coated surface to prepare a 25 μm-thick pigmented adhesive material having release films having different release forces on both sides, and used for bonding the AR film. When bonding, peel off the release film on one side and paste it on the conductive laminate, then peel off the other release film and paste the AR film to produce an optical filter for the plasma display panel. did.
The surface resistivity of the produced conductive laminate is 1.5Ω / □, and the light transmittance in the near-infrared wavelength region as an optical filter for a plasma display panel is 20% or less over 800 to 1000 nm, particularly 820 nm, The light transmittances at 850 nm and 950 nm were 3.8%, 2.4% and 0.7%, respectively. The surface resistivity was measured by an eddy current method (measurement equipment: HEHIGHTON Electronics, Inc., Contactless Measurement System).
In addition, no significant change was observed in the transmittance even after the environmental test, and it was confirmed that the optical filter of the present invention had sufficiently suitable characteristics for plasma display panels from the viewpoint of durability and characteristics.

  The present invention can be used for any optical member in which a conductive thin film is used. By forming a thin film layer containing a specific element on the surface of a conductive laminate containing zinc oxide, the conductive laminate can be prevented from deteriorating the adhesive layer provided on the conductive laminate. It is possible to provide an optical filter that is superior in terms of durability and characteristics, taking advantage of the function of the member to be bonded and the function of the member to be bonded, and its industrial utility value is high.

Claims (4)

At least one unit of high refractive index thin film layer (a) and metal thin film layer (b) containing silver or silver alloy is formed on (a) / (b) on at least the transparent substrate (A). Further, a high refractive index thin film layer (c) containing zinc oxide is further laminated thereon, and the high refractive index thin film layer (c) containing zinc oxide is further laminated on Group 5 or Group 5 of the periodic table. A conductive laminate in which a thin film layer (d) containing at least one group 6 element is formed, and an adhesive layer formed on the thin film layer (d) so as to be in contact with the thin film layer (d) ( An optical filter comprising B). 2. The optical filter according to claim 1, wherein the structural unit of (a) / (b) is formed in a range of 1 unit to 7 units. The optical filter according to claim 1 or 2, wherein the thin film layer (d) contains at least one element selected from tantalum or niobium. 4. The optical filter according to claim 1, wherein the optical filter is used for a plasma display panel.