DE112005000216T5 - Electromagnetic wave shielding film and method of making the same - Google Patents

Abstract

Sheet for shielding electromagnetic waves, the
a transparent substrate and
a metal mesh layer laminated with a bonding agent layer on a surface of the transparent substrate;
a first copper-containing blackening layer formed on one surface of the metal mesh layer on the side of the transparent substrate; and a second anticorrosive layer containing one or more metals selected from chromium, nickel, and silicon are formed on the other surface of the metal mesh layer on the side opposite to the transparent substrate.

Description

Territory of invention

The The present invention relates to a sheet for shielding electromagnetic Waves to prevent an EMI (electromagnetic interference), the caused by electromagnetic waves passing through screens such as. Cathode ray tubes (hereinafter also referred to as CRT's and plasma screens (hereinafter also referred to as PDPs) be, and in particular a sheet for shielding electromagnetic Ripples the visibility of an image on a display or a screen is displayed, not impaired, and that can be made in a small number of steps, and a method of manufacturing the electromagnetic shielding sheet Waves.

In this description refers to "ratio", "part", "%" and the like, indicate the proportions by weight unless otherwise stated is, and the symbol "/" indicates that layers, which are listed together with this symbol, integrally laminated are. "EMI", "NIR" and "PET" refer to "electromagnetic (Waves) interference "," near-infrared rays "or" polyethylene terephthalate "and it is to abbreviations, Synonyms, functional expressions, common Terms or terms used in the art.

technical background

electromagnetic disorders have in recent years due to advances in performance electrical and electronic devices and also due to the increasing Use of these devices increased. Even screens like CRT's and produce PDP's electromagnetic waves. A PDP is an arrangement that consists of a Glass substrate, which has a data electrode and a fluorescent layer and a glass substrate having a transparent electrode has, is composed. In operation, such emits Screen not only visible light from which a picture on the Screen is generated, but also electromagnetic waves, Near infrared rays and heat in big Amounts. In general, on the front of a PDP is a front panel mounted, which is a sheet for shielding electromagnetic waves contains to shield the electromagnetic waves generated by the PDP. Such a front panel must be electromagnetic during shielding Waves with frequencies from 30 MHz to 1 GHz from the front of the screen are emitted, an efficiency of 30 dB or have more. The front panel also needs to use near-infrared rays wavelength from 800 to 1100 nm shield from the front of the screen be emitted because these rays malfunction other devices, such as e.g. of video recorders.

Around to enable that an image displayed on the screen is clearly visible remains, the material needs to shield electromagnetic waves be less visible (where the unrecognizability is high) and it must have adequate transparency as a whole (permeability for visible Light).

Further are PDP's by it that they are big Have screens, and leaves for shielding electromagnetic waves for such PDP's are large (outer dimension), the sizes of which are, for example 621 × 831 mm for 37 inch screens and 983 × 583 mm for 42 inch screens and even larger sizes exist. this fact requires a manufacturing process that handles large materials is appropriate. Total need the leaves for shielding electromagnetic waves shielding properties in terms of electromagnetic waves and less visible materials for shielding electromagnetic waves with a reasonable Transparency be made so that they have the visibility of the displayed Do not interfere with pictures and there is a need for a manufacturing method by which a sheet for shielding electromagnetic Waves made in a small number of steps with a high productivity can be.

State of technology

to Production of leaves for shielding electromagnetic waves containing metal network layers, were customary the following two methods are used.

One of the known methods is that an electroconductive ink or a photosensitive coating liquid containing a chemical plating catalyst is applied to the entire surface of a transparent substrate, and photolithographically coating the coating nem network is formed, which is then plated with a metal (see, for example, the patent documents 1 and 2). However, this method is disadvantageous in that, since the metal layer surface on the side of the transparent substrate can not be blackened, it is impossible to avoid a reduction in image visibility caused by external light such as sunlight falling on the metal mesh This is reflected, is caused. Further, in the manufacturing method, when an electroconductive ink is used, it is required for plating a longer time because the electric resistance of the electroconductive ink is high, and therefore the productivity is low. Further, this method has also been disadvantageous in that the metal net is oxidized in the air and undergoes a change of properties to have an increased electrical resistance, resulting in deterioration of the electromagnetic wave shielding properties.

Another known method is as follows: A copper mesh layer having line portions defining a plurality of openings is laminated with an adhesive layer on a PET film (transparent substrate), and the surfaces, back surfaces, and side surfaces of the line portions of the copper mesh layer are subjected to a blackening treatment (See, for example, Patent Document 3). However, the blackening treatment is a chemical conversion treatment, and needle crystals are formed so that the thus formed blackening layer easily falls or is deformed. Moreover, since the treatment is performed at a high temperature, the laminate tends to roll and its appearance is adversely affected.
Patent Document 1: Japanese Patent Laid-Open Publication No. 13088/2000,
Patent Document 2: Japanese Patent Laid-Open Publication No. 59079/2000, and
Patent Document 3: Japanese Patent Laid-Open Publication No. 9484/2002.

Summary the invention

The The present invention has been made to be as described above To solve problems in the prior art. An object of the present The invention is therefore the provision of a sheet for shielding electromagnetic waves, which provide adequate transparency, excellent Shielding properties for electromagnetic waves, excellent non-recognizability its network and looks great, none Deterioration of its shielding properties for electromagnetic Waves undergo a metal oxidation, and that the visibility a picture displayed on a screen does not affect and a manufacturing process by which the sheet for shielding electromagnetic waves in a small number of steps can be produced.

The The present invention is a sheet for shielding electromagnetic Waves, which is a transparent substrate and one with an adhesive layer on a surface of the transparent substrate laminated metal mesh layer, a first, Copper-containing blackening layer, the one on a surface the metal mesh layer on the side of the transparent substrate is formed, and a second anticorrosive layer containing a or contains more metal (s), which is selected from chromium, nickel and silicon and are on the other surface of the metal mesh layer opposite the page the transparent substrate is formed comprises.

The The present invention is the electromagnetic shielding sheet Shaft, further comprising a first corrosion protection layer, the contains one or more metal (s), which is selected from chromium, nickel and silicon and between the first blackening layer and the transparent one Substrate is formed.

The The present invention is the electromagnetic shielding sheet Waves where the side surfaces the first blackening layer, the metal layer and the second anticorrosion layer on the transparent substrate, and the front surface of the second anticorrosion layer completely with a second blackening layer are covered.

The The present invention is the electromagnetic shielding sheet Waves where the side surfaces the first anti-corrosion layer, the first blackening layer, the metal layer and the second anticorrosive layer on the transparent substrate, and the front surface of the second Corrosion protection layer completely with a second blackening layer are covered.

The present invention is the electromagnetic wave shielding sheet in which the second blackening layer has been formed by plating and at least one metal selected from copper, cobalt, nickel, zinc, molybdenum, tin and chromium, or a compound of any of them or an alloy consisting of two or more of these metals.

The The present invention is a method of making a sheet for shielding electromagnetic waves, comprising the steps of Producing a metal layer, sequentially forming a first blackening layer and a first anticorrosion layer on the surface of the Metal layer on the side of a transparent substrate, forming a second anti - corrosion layer on the other surface of the Metal layer on the side opposite to the transparent substrate, the Laminating the metal layer and the transparent substrate with an adhesive layer, wherein the anti-corrosion layer is the transparent Substrate opposite is to form a laminate, and the etching of the laminate for training the metal layer comprises a network.

The The present invention is the process for producing a sheet for shielding electromagnetic waves, wherein at least one the first corrosion protection layer and the second corrosion protection layer contains one or more metal (s), nickel, chromium and silicon, and also zinc and / or Tin, if it is initial is formed, selected is or, and the zinc and / or tin from the first corrosion protection layer and / or the second anticorrosion layer in the step of etching becomes.

The The present invention is the process for producing a sheet for shielding electromagnetic waves, in which after the step of the etching the side surfaces the first anti-corrosion layer, the first blackening layer, the metal layer and the second anticorrosion layer used in the laminate, and the front surface of the second anticorrosion layer Completely with a second blackening layer to be covered.

The The present invention provides a sheet for shielding electromagnetic Waves ready, providing adequate transparency, excellent shielding properties for electromagnetic Waves and a great unknowability of his web has the visibility of one displayed on a screen Image not affected and no deterioration of the shielding properties for electromagnetic Waves undergo oxidation by a metal layer.

The The present invention provides a sheet for shielding electromagnetic Waves ready, with adequate transparency and excellent Shielding properties for has electromagnetic waves and that the reflection of light better prevent from a network, especially in a bright environment can make the network less recognizable and consequently the visibility a picture displayed on a screen.

The The present invention provides a process for the preparation of a Sheet for shielding electromagnetic waves ready, in which a corrosion protection layer can be easily formed and through this is a very good durable Sheet for shielding electromagnetic waves are generated can.

Short description the drawings

1 is a plan view of an inventive sheet for shielding electromagnetic waves,

2 is a perspective view, the in the 1 shown power supply shows

3 is a sectional view of a power supply of an electromagnetic wave shielding sheet according to the invention, and

4 is a sectional view of a power supply of a sheet according to the invention for shielding electromagnetic waves.

Best way of execution the invention

Basics

Embodiments of the present invention will be described below with reference to the accompanying drawings. As it is in the 1 and 2 1, an electromagnetic wave shielding sheet 1 basically comprises a power supply 103 and optionally a frame part 101 around the power supply 103 for grounding. As it is in the 3 (A) 1, which is a sectional view, includes the electromagnetic wave shielding sheet 1 a transparent substrate 11 and a metal mesh layer 21 covered with a transparent adhesive layer 13 on a surface of the transparent substrate 11 is laminated. On a surface of the metal mesh layer 21 on the side of the transparent substrate 11 is a first blackening layer 25A trained as it is in the 3 (A) is shown. In some other figures, a second corrosion protection layer is 23B on the other surface of the metal mesh layer 21 on the side opposite the transparent substrate 11 educated. Alternatively, a first blackening layer 25A and a first anti-corrosion layer 23A consecutively on the surface of the metal mesh layer 21 on the side of the transparent substrate 11 be trained as it is in the 3 (B) is shown.

In the 1 and 2 is the power adapter 103 from the line parts 107 composed of a plurality of openings 105 define. The line parts 107 have the metal layer 21 , the first blackening layer 25A and the optional first anti-corrosion layer 23A that are on the surface of the metal layer 21 on the side of the transparent substrate 11 and the second anti-corrosion layer 23B on the other surface of the metal layer 21 on the side opposite the transparent substrate 11 on. The 3 (A) and 3 (B) and the 4 (A) and 4 (B) are sectional views along the line AA of 2 , where the line parts 107 along the BB line of 2 are formed.

Furthermore, as can be seen in the 4 (A) is shown, a second blackening layer 25B be formed so that they the front surface (surface) and the side surfaces of [first blackening layer 25A / Metal layer 21 / first corrosion protection layer 23A ] covered in the form of a net.

As it is in the 4 (B) can be shown, a second blackening layer 25B be designed so that they the front surface (surface) and the side surfaces of [first anticorrosion layer 23A / first blackening layer 25A / Metal layer 21 / second corrosion protection layer 23B ] covered in the form of a net.

The above-described first blackening layer 25A / Metal layer 21 / second corrosion protection layer 23B ], [first corrosion protection layer 23A / first blackening layer 25A / Metal layer 21 / second corrosion protection layer 23B ], [first blackening layer 25A / Metal layer 21 / first corrosion protection layer 23A / second blackening layer 25B ] and [first anti-corrosion layer 23A / first blackening layer 25A / Metal layer 21 / second corrosion protection layer 23B , second blackening layer 25B ] are electromagnetic wave shielding layers, and each electromagnetic wave shielding layer includes the power supply 103 serving as an image display part, and optionally the frame part 101 ,

method

In the manufacture of the electromagnetic wave shielding sheet according to the present invention, the first anticorrosive layer becomes 23A and the second anticorrosion layer 23B prepared so as to contain one or more metals selected from chromium, nickel and silicon (or all of these metals) when formed. Alternatively, these layers may be provided to contain zinc and / or tin in addition to these metals when they are initially formed and the zinc and / or tin to be removed in the intermediate step such that the layers eventually become the one or the plurality of metal (s) selected from chromium, nickel and silicon. The other steps may be effected in a conventional manner.

For example, a method for producing [transparent substrate 11 / Adhesive layer 13 / first corrosion protection layer 23A / first blackening layer 25A / Metal layer 21 / second corrosion protection layer 23B / second blackening layer 25B ], ie, a laminate comprising the largest number of constituent layers, steps (1) of forming a metal layer, (2) forming a first blackening layer on one surface of the metal layer, and first and second anticorrosive layers on both sides of the metal layer, (3) laminating the metal layer and a transparent substrate with an adhesive, the first anticorrosion layer facing the transparent substrate, (4) photolithographically forming the first anticorrosive layer, the first blackening layer, the metal layer, and the second anticorrosive layer on the transparent substrate Substrate have been formed into a mesh pattern, and (5) subjecting the mesh pattern to a blackening treatment to form a second blackening layer.

metal layer

For the metal layer 21 For example, a metal having an electrical conductivity that is good enough to satisfactorily shield electromagnetic waves, such as gold, silver, copper, iron, nickel or chromium may be used. Of these metals, iron and copper are preferable because they have high electrical conductivity (and also high magnetic permeability), which contributes to the formation of electromagnetic wave shielding properties, exhibit excellent etching processability, and are relatively inexpensive. Copper is preferred when particularly high electrical conductivity is required, and iron is preferred when high magnetic permeability or high hysteresis loss is required in addition to electrical conductivity. The metal layer may not only be a single metal layer, but may also be an alloy layer or a multi-layer layer. Low-carbon steels, such as low-carbon unrefined steels and low-carbon aluminum-tempered steels, Ni-Fe alloys and invar alloys are preferred as iron materials herein. When cathodic electrodeposition is performed as a blackening treatment, it is preferable to use a copper or copper alloy foil as a metal layer because it is easy to electrodeposit a blackening layer on such a material. Although both a rolled copper foil and an electrolytic copper foil can be used as a copper foil, an electrolytic copper foil is less than a thickness due to its uniform thickness and adhesion to a layer formed by a blackening treatment and / or a chromate treatment May have 10 microns, preferably. The thickness of the metal layer 21 is about 1 to 100 microns, and preferably 5 to 20 microns. If the metal layer 21 has a thickness lower than the above-mentioned range, it has an increased electrical resistance value, and thus exhibits an impaired electromagnetic wave shielding effect, though it can be easily photolithographically processed into a mesh. If the metal layer 21 has a thickness over the above range, it can not be formed into the desired fine mesh. As a result, the mesh has a significantly reduced opening rate and reduced light transmission, resulting in a smaller viewing angle and less image visibility.

The surface roughness of the metal layer 21 is about 0.1 to 10 microns, preferably 0.5 to 10 microns, indicated as Rz value. If the metal layer 21 has a surface roughness below this range, mirror reflection of external light takes place even when subjected to a blackening treatment, and hence the image visibility is lowered. When the surface roughness of the metal layer 21 is above the above-mentioned range, an adhesive or a photoresist after it has been applied does not spread over the entire surface of the metal layer or comprises air, so that air bubbles are generated. The surface roughness Rz here is an average of 10 measurements obtained in accordance with JIS-B0601 (version 1994).

First blackening layer

A blackening treatment to form the first blackening layer 25A (the formation of a blackening layer is hereinafter referred to as blackening treatment) is performed when the metal layer 21 still present in the state of a single layer. The blackening treatment may be performed by roughening or blackening the surface of the metal layer, and the deposition of a metal, an alloy, a metal oxide or a metal sulfide or various other techniques may be used for this treatment. Preferred methods of performing the blackening treatment include plating, and plating allows the formation of a blackening layer on the metal layer 21 with good adhesion and easy uniform blackening of the surface of the metal layer 21 , As for the materials for plating, when copper is used for the metal layer, a copper-containing material is preferable from the viewpoint of adhesion to the metal layer. In particular, copper itself, a copper-containing compound or a copper-containing alloy is used.

For example, copper oxide, copper sulfide or an alloy or compound containing copper as an essential component and at least one metal selected from cobalt, nickel, zinc, molybdenum, tin and chromium may be used. When such a copper-containing metal in the first blackening layer 25A can be converted between the first blackening layer 25A and the metal layer 21 , in particular a copper layer, excellent adhesion can be obtained. If other metals or compounds are used, the metal layer may 21 not completely blackened or the adhesion of the blackening layer to the metal layer 21 is insufficient. These difficulties occur significantly in the case where, for example, cadmium is used for plating.

at The use of copper itself, as fine particles of copper deposited on the metal layer, reflected light through the fine particles are distributed or partially absorbed, so that the Amount of reflected light per direction is reduced, causing the metal layer blackened becomes. In this case is the surface roughness the layer of fine copper particles preferably about 0.1 to 3 μm, like it is indicated by the Rz value.

A plating method which is preferably used when a copper foil as a metal layer 21 is a cathodic electrodeposition plating in which the copper foil is subjected to cathodic electrolysis in an electrolyte such as sulfuric acid, copper sulfate or cobalt sulfate, thereby depositing cationic particles on the copper foil. The deposited cationic particles roughen the copper foil and simultaneously lead to a black color of the copper foil. Although the cationic particles may be either copper particles or particles of an alloy of copper and another metal, copper-cobalt alloy particles are preferred herein. The average particle diameter of the copper-cobalt alloy particles is preferably 0.1 to 1 μm.

The Cathodic electrodeposition is for the deposition of particles with uniform size with one average particle diameter of 0.1 to 1 micron appropriate. Furthermore, the surface of the Copper foil cathodic when treated with a high current density and generates reducing hydrogen so that it becomes activated so that between the copper foil and the particles a significant improved adhesion can be obtained. In the case where the average particle diameter of the copper-cobalt alloy particles outside of the above-described range is when the average particle diameter of the copper-cobalt alloy particles over the above range, the blackness of the copper foil is insufficient and above In addition, the particles fall off easily (also as falling off the powdery one Coating called) instead. In addition, the external appearance indicates The agglomerated particles have a poor density and ununiformity Appearance and light absorption are noticeable. Copper-cobalt alloy particles having an average particle diameter below that described above Area are also regarding the blackening power insufficient and can not completely prevent a reflection of external light, so that the Image visibility is lower.

First and second corrosion protection layer

Thereafter, a first corrosion protection layer 23A on one surface of the blackening layer 25A on the metal layer 21 trained and a second corrosion protection layer 23B becomes on the other surface of the metal layer 21 educated. The first and the second corrosion protection layer 23A . 23B can on both sides of the metal layer 21 be formed either simultaneously or sequentially. The first corrosion protection layer 23A and the second anticorrosion layer 23B each have the function of protecting the surface of the first blackening layer 25A and the surface of the metal layer 21 Before corrosion and, moreover, when particles are used for the blackening treatment, these layers may prevent the particles from falling off or deforming. To a drop or deformation of the particles with which the first blackening layer 25A is designed to prevent, it is essential to use the first anticorrosive coating 23A provide. Although conventional anticorrosive coatings as the first anticorrosive coating 23A and / or second corrosion protection layer 23B Here, one or more metals selected from nickel, chromium and silicon are used as materials for these anticorrosive layers. For example, chromium, nickel, chromium + nickel, chromium + nickel + silicon and oxides of these metals are preferable, and a material containing chromium, nickel and silicon is particularly preferable. The thickness of each anticorrosion layer is about 0.001 to 1 μm, preferably 0.001 to 0.1 μm.

Chrome, Nickel, chromium + nickel, chromium + nickel + silicon or an oxide Any of these metals is made by a conventional plating process deposited to form a corrosion protection layer and in the present invention, it is preferable to first form a layer the additional to one or more metal (s) made of nickel, chromium and silicon selected is or are, contains zinc and / or tin.

In the case where the first anti-corrosion layer 23A and the second anticorrosion layer 23B Containing nickel, these layers exhibit considerably improved corrosion resistance and can prevent the blackening layer from falling off with greater certainty because the nickel has been passivated.

To silicon in the first anticorrosion layer 23A and / or the second corrosion protection layer 23B For example, a silicon-containing compound, preferably a silicon-containing compound such as a silane coupling agent, may be added to a plating bath. Because the first corrosion protection layer 23A and / or the second corrosion protection layer 23B containing silicon containing a significantly improved corrosion resistance, such a layer remains even after the step of peeling a photoresist with an alkaline solution effected by a photolithographic process which will be described later.

transparent substratum

As a transparent substrate 11 For example, various materials having transparency, insulating properties, heat resistance, mechanical strength, etc. that are good enough to withstand the conditions of use and manufacture can be used. Examples of materials suitable herein include glass and transparent resins. Glass includes quartz glass, borosilicate glass, and soda-lime glass, and it is preferred to use a non-alkali glass which does not contain alkali components and which has a low rate of thermal expansion and dimensional stability, and also excellent high temperature heat treatment processing properties. A non-alkali glass substrate may be provided so as to serve also as a substrate for an electrode.

Examples for transparent Resins suitable herein include polyester resins, such as e.g. Polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, Terephthalic acid-isophthalic acid-ethylene glycol copolymers and terephthalic acid cyclohexanedimethanol-ethylene glycol copolymers; Polyamide resins, e.g. Nylon 6; Polyolefin resins, e.g. polypropylene and polymethylpentene; Acrylic resins, such as e.g. polymethyl methacrylate; Styrene resins, e.g. Polystyrene and styrene-acrylonitrile copolymers; Cellulose resins, such as e.g. triacetylcellulose; Imide resins and polycarbonate. A sheet, a film, a plate or the like of any of these Resins can be used as a transparent substrate.

The transparent substrate, which is a film, a plate or the like is made of the transparent resin, may consist of a Copolymer resin or a mixture (including an alloy), the as a main component, any of the above enumerated resins contains or it can also be a laminate of two or more layers act. Although such a transparent substrate either an oriented or a non-oriented film can be preferably uses a mono- or biaxially oriented film, to an increased To obtain strength. In general, the thickness of the transparent is Substrate about 12 to 1000 microns. However, the preferred thickness is 50 to 700 microns and the optimum Thickness is 100 to 500 μm, if for the transparent substrate is a transparent resin is used. If glass for the transparent substrate is used, the preferred thickness is about 1000 to 5000 μm. In any case, a transparent substrate with a thickness below the range mentioned above is not sufficiently high mechanical Have firmness so that it curls, becomes wavy or is destroyed, while a transparent substrate having a thickness above the above Range an overly high Strength, which is a waste in terms of cost represents.

in the In general, a film of a polyester resin, e.g. polyethylene terephthalate or polyethylene naphthalate, a cellulose resin film or a glass plate appropriate as transparent substrate used as it is both an excellent Transparency as well as excellent heat resistance and also cheap is. Of these materials, a polyethylene terephthalate film is most preferably, because it is difficult to destroy, a low weight and can be easily shaped. A transparent substrate with a higher one Transparency is better and the preferred transparency is given as permeability for visible Light, amounts 80% or more.

In front the application of an adhesive, the surface of the transparent substrate film, which is to be coated with the adhesive, an adhesion-improving Treatment, such as a corona discharge treatment, a plasma treatment, an ozone treatment, a flame treatment, a primer coating treatment (The bonding agent is also used as an anchoring agent, adhesion promoting or adhesion improving agent), a preheating treatment, a dust removal treatment, a vacuum deposition or a Subjected to alkali treatment. In the resin film may optionally additives such as. Ultraviolet absorbers, fillers, plasticizers and antistatic agents be included.

laminating

The transparent substrate 11 and the above-described first anticorrosion layer 23A or the first blackening layer 25A that are on the metal layer 21 be located with an adhesive 13 to form a laminate 1a laminated. This lamination process proceeds as follows: An adhesive resin or mixture of adhesive resins is transferred to a fluid such as a latex, an aqueous dispersion, or an organic solvent solution, which is then applied to the surface of the transparent substrate 11 or on the surface of the first anti-corrosion layer 23A or the surface of the first blackening layer 25A or printed on these two surfaces by a conventional printing or coating process, such as screen printing, gravure, comma layers or roll coating, and optionally dried. Then the opposing material is placed on the adhesive layer and pressure is applied and the adhesive is then cured. The thickness of the adhesive layer (when dried) is about 0.1 to 20 μm, preferably 1 to 10 μm.

In particular, in the lamination process, the metal layer usually becomes 21 and the transparent substrate 11 used in continuous band-shaped (rolled up) forms. Specifically, the adhesive is applied to the metal layer and / or the substrate film in a state of being unrolled and stretched by a take-up roll, and then dried. The other material is placed on this adhesive layer and pressure is applied. The obtained material is further subjected to aging (aging and hardening) in an atmosphere at 30 to 80 ° C for several hours to several days as occasion demands, thereby obtaining a rolled laminate. It is preferred to use a method which is referred to as dry lamination by those skilled in the art.

dry laminating

The Dry lamination is a method of laminating two types of materials in the following way: By a coating process, such as. Roll, reverse roll or gravure coating becomes a Adhesive in a solvent dispersed or dissolved is applied to one of the two materials so that the dried Layer has a thickness of about 0.1 to 20 microns, preferably 1 to 10 microns, and the solvent is evaporated to form an adhesive layer. Immediately after the formation of the adhesive layer becomes the other laminating material placed on the adhesive layer and this laminate becomes several Hours to several days at 30 to 80 ° C aged to the adhesive to harden. The adhesive used in dry lamination can, includes adhesives made from thermosetting resins are. Special examples for thermosetting resin adhesives, suitable herein include two-part curing urethane adhesives, the polyfunctional isocyanates, e.g. toluene diisocyanate or hexamethylene diisocyanate with hydroxyl group-containing compounds, such as. Polyether polyols or Polyacrylatpolyolen be obtained can; Acrylic adhesive and rubber adhesive. Of these adhesives are two-component-curing Urethane adhesive preferred.

alternative For example, a method can be used in which a by ionizing Radiation curing resin as an adhesive instead of the thermosetting Resin is used and ionizing radiation to cure the Resin is applied. In this case, ionizing radiation is commonly used Ultraviolet light or an electron beam used.

The [first blackening layer 25A / Metal layer 21 / second corrosion protection layer 23B ] in the laminate 1a from [transparent substrate 11 / Adhesive layer / first blackening layer 25A / Metal layer 21 / second corrosion protection layer 23B ] or the [first anticorrosion layer 23A / first blackening layer 25A / Metal layer 21 / second corrosion protection layer 23B ] in the laminate 1a from [transparent substrate 11 / Adhesive layer / first anti-corrosion layer 23A / first blackening layer 25A / Metal layer 21 / second corrosion protection layer 23B ] are photolithographically formed into a mesh pattern.

photolithographic method

A patterned photoresist layer is formed on the surface of the second anticorrosion layer 23B in the laminate described above 1a formed, those portions of the metal layer 21 which are not covered with the photoresist layer are removed by etching, and the photoresist layer is then peeled off, thereby obtaining an electromagnetic wave shielding layer in a mesh pattern. As it is in the 1 is shown, the electromagnetic wave shielding layer consists of a power supply 103 and an optional frame part 101 , Further, the power supply points 103 as it is in the 2 shown is line parts 107 on, which are the remaining portions of the metal layer 21 trades through the openings 105 be defined while the frame part 101 no openings 105 and completely made of the remaining metal layer 21 consists. The frame part 101 is optional and can be provided so that it has the power adapter 103 surrounds or at least part of the area around the power supply 103 covered.

The method described above is for processing the band-shaped laminate 1a in the form of a continuously wound roll. While the laminate 1a either continuously or discontinuously unwound and transported, masking, etching and peeling of the photoresist are performed on stretched and non-loose laminate. First, masking is performed in the following manner. For example, a photosensitive photoresist is applied to the metal layer 21 and dried, this photoresist is subjected to contact exposure using an original plate having a predetermined pattern (consisting of the line parts of the power supply and the frame part), followed by development with water, a film hardening treatment and a heat treatment. The application of the photoresist is carried out in the following manner: While the band-shaped wound laminate is unwound and transported continuously or discontinuously, a photoresist made of casein, PVA or gelatin becomes the side of the metal layer 21 of the laminate by a method such as dipping, curtain coating or flood coating applied. Alternatively, a dry film resist can be used as the resist, and the use of a dry film resist can improve the processing efficiency. When casein is used as a photoresist, the heat treatment is usually carried out by heating, and in this case, it is preferable to make the temperature of heating as low as possible to prevent curling of the laminate.

etching

The etching becomes performed after masking. Because the etching carried out continuously it is preferred, as an etchant to use an iron (III) or copper (II) chloride solution that is light in weight be circulated can. It is also possible this etching step through the use of facilities to make a shadow mask for one cathode ray tube a color TV perform, where a band-shaped continuous steel starting material, in particular a thin plate with a thickness of 20 to 80 μm, etched becomes. In particular, it is possible the existing facilities for making the shadow mask to use and a series of steps from masking to etching continuously to do so that the manufacturing efficiency is extremely high. After etching is the laminate washing with water, peeling the photoresist with a alkaline solution and subjected to cleaning and then dried.

With the alkaline solution used to dissolve the photoresist, the tin or zinc becomes the second anticorrosion layer 23B , which is exposed to the surface, elutes. To remove the tin or zinc from the first anticorrosion layer 23A and the second anticorrosion layer 23B , which are present on the two surfaces of the laminate, becomes the first anticorrosion layer 23A on the metal layer 21 is formed, subjected to alkali treatment, before being applied to the transparent substrate 11 is laminated, whereby the tin or zinc in advance from the first anti-corrosion layer 23A Will get removed. It is therefore not necessary to include the step of removing the tin or zinc from the first anti-corrosion layer 23A and from the second anticorrosion layer 23B and thus the number of steps as a whole does not increase.

network

The power supply 103 is a surface of the frame part 101 is surrounded. The power supply 103 has line parts 107 on which a plurality of openings 105 define. The openings 105 are not limited in shape (mesh pattern) and the shape of the openings 105 may be a triangle such as an equilateral triangle, a square such as a regular square, a rectangle, a rhombus or a trapezoid, a polygon such as a hexagon, a circle, an oval, or the like. The power supply 103 is a combination of a majority of these openings 105 , With respect to the opening rate and the unrecognizability of the net, the line width W is 50 μm or less, preferably 20 μm or less, and in view of the light transmittance, the line pitch P (line distance) is 125 μm or more, preferably 200 μm or more , The opening rate is preferably 50% or more. In order to prevent the occurrence of moiré fringes or the like, the skew angle (the angle between the line part of the mesh and the sides of the electromagnetic wave shielding sheet) may be properly selected in consideration of the pixel and emission characteristics of a screen.

Second blackening layer

Although the same material and the same process as used to form the first blackening layer 25A used to form the second blackening layer 25B can be used For example, black chrome, black nickel, nickel alloys and the like may also be used. The nickel alloys useful herein include nickel-zinc alloys, nickel-tin alloys, and nickel-tin-copper alloys. In particular, nickel alloys have excellent electrical conductivity and blackness. Furthermore, the second blackening layer 25B be prepared to have the function of preventing corrosion of the metal layer in addition to the blackening effect 21 having.

In general, the particles with which the second blackening layer 25B is formed needle-shaped, so that they are easily deformed by external forces and subject to a change in appearance. However, nickel alloy particles are not easily deformed and the subsequent steps are with the exposed surface of the second blackening layer 25B are effected, the use of a nickel alloy is more preferred. A conventional electroplating method or electroless plating method may be used to deposit a nickel alloy. Deposition of a nickel alloy may be effected after performing nickel plating.

blackening

By performing a blackening treatment in the above-described manner, it is possible to have the front surfaces (surfaces) of the line parts (the surfaces of the protrusions) and even the side surfaces of the line parts (the side surfaces of the protrusions) of the metal mesh layer 21 to blacken. Consequently, the patterned metal mesh layer becomes 21 completely with the first blackening layer 25A and the second blackening layer 25B covered. Therefore, the electromagnetic wave shielding metal line part (line parts) can shield electromagnetic waves generated by a PDP, and does not reflect any external light from fluorescent lamps or the like nor the screen light from the PDP. It is thus possible to view a high contrast image in good condition on the PDP.

In In this description, the roughening and the blackening become together as a blackening treatment designated. The preferred reflection value Y of the blackening layer is about 15 or less, preferably 5 or less, more preferably 2.0 or less. Measurements of the reflection value Y were made using Spectrophotometer UV-3100PC (manufactured by Shimadzu Corp., Japan) at an angle of incidence of 5 ° (wavelength: from 380 to 780 nm).

The sheets according to the invention Shielding of electromagnetic waves can be combined with others optical elements are used as front panels for PDP's. For example, can a combination of the sheet to shield electromagnetic Waves and an optical element that has the function of absorption of near-infrared rays, absorbing near-infrared rays, which are emitted by a PDP, causing them to malfunction a remote-controlled device, an optical communication device and the like, near the PDP can be used. Furthermore, a combination reflects the sheet for shielding electromagnetic waves and a optical element that has the function of preventing a reflection and / or a glare of light, neither the screen light from a PDP, still external light that falls on the PDP from outside, so that it can improve the image visibility.

In the case where the frame part 101 is provided, this part is also simultaneously with the power supply 103 blackened and thus more intense black, so that a screen on which such a sheet for shielding electromagnetic waves is mounted, high-class appears.

Furthermore indicates from the leaves of the invention to Shielding electromagnetic waves a sheet for shielding electromagnetic waves, the blackening layers on both Has sides, a layer for shielding electromagnetic Waves on both surfaces have a black color, so that such a sheet for shielding electromagnetic waves can be mounted on a PDP that one of the pages is directed to the PDP.

If a flexible material for the transparent substrate 11 is used, it is possible to process in each step a belt-shaped, continuously rolled (wound) transparent substrate while it is unwound and transported continuously or discontinuously. Thus, an electromagnetic wave shielding sheet can be manufactured in a reduced number of steps with a high productivity, causing two or more steps together in one step.

modified embodiments

• (1) Obwohl ein Laminierverfahren unter Verwendung eines Haftmittels zum Laminieren des transparenten Substrats 11 und von [Korrosionsschutzschicht 23A/erste Schwärzungsschicht 25A/Metallschicht 21] verwendet worden ist, um das Laminat 1a zu bilden, ist es nicht erforderlich, das Haftmittel zu verwenden. Beispielsweise können, nachdem die Oberfläche des transparenten Substrats 11 elektrisch leitfähig gemacht worden ist, die erste Schwärzungsschicht 25A und die Metallschicht 21 auf dieser Oberfläche durch ein herkömmliches stromloses Plattierungsverfahren oder Elektroplattierungsverfahren gebildet werden.
• (2) Nach dem Erhalten eines solchen Blatts zur Abschirmung elektromagnetischer Wellen 1, wie es in der 3 oder der 4 gezeigt ist, kann die Oberfläche des Netzteils 103, die rau ist (aufgrund der Unregelmäßigkeiten, die durch die Linienteile 107 und die Öffnungen 105 bewirkt werden), durch Füllen der Öffnungen 105 mit einem transparenten Harz geglättet werden. Dadurch verbleiben keinerlei Luftblasen in den Öffnungen 105, wenn der Netzteil des Blatts zur Abschirmung elektromagnetischer Wellen und ein anderes Element (ein transparentes Substrat, ein Nahinfrarotstrahlen-absorbierender Filter, ein Antireflexionsfilter oder dergleichen) in dem späteren Schritt mit einer Haftmittelschicht laminiert werden. Es ist folglich möglich, eine Verminderung der Schärfe eines angezeigten Bilds zu vermeiden, die auftritt, wenn Luftblasen, die in den Öffnungen verbleiben, Licht streuen.

The present invention includes the following modifications.

• (1) Although a laminating method using an adhesive for laminating the transparent substrate 11 and of [anticorrosive coating 23A / first blackening layer 25A / Metal layer 21 ] has been used to laminate 1a it is not necessary to use the adhesive. For example, after the surface of the transparent substrate 11 has been made electrically conductive, the first blackening layer 25A and the metal layer 21 are formed on this surface by a conventional electroless plating method or electroplating method.
• (2) After obtaining such a sheet for shielding electromagnetic waves 1 as it is in the 3 or the 4 shown can be the surface of the power supply 103 that is rough (due to the irregularities caused by the line parts 107 and the openings 105 be effected), by filling the openings 105 be smoothed with a transparent resin. As a result, no air bubbles remain in the openings 105 when the AC adapter of the electromagnetic wave shielding sheet and another member (a transparent substrate, a near-infrared ray absorbing filter, an antireflection filter or the like) are laminated with an adhesive layer in the later step. It is thus possible to avoid a reduction in the sharpness of a displayed image that occurs when air bubbles remaining in the openings scatter light.

Examples

The The present invention will be described more specifically below by way of examples and a comparative example. The present invention however, is not limited to the following examples.

example 1

An electrolytic copper foil with a thickness of 10 μm was used as a metal layer 21 used. Copper-cobalt alloy particles (average particle diameter: 0.3 μm) were deposited by cathodic electrodeposition on a surface of the metal layer 21 deposited, whereby a blackening treatment to form a first blackening layer 25A was carried out.

Subsequently, the other surface of the metal layer 21 on the side opposite to the side of the first blackening layer 25A a zinc plating and a chromate treatment, whereby a second corrosion protection layer 23B containing zinc and chromium on this surface of the metal layer 21 was trained.

The combination of the metal layer 21 , the second anti-corrosion layer 23B and the first blackening layer 25A was on a transparent substrate 11 which was made of a biaxially oriented 100 μm PET film A4300 (a mark of a polyethylene terephthalate film, manufactured by Toyobo Co., Ltd., Japan) with an adhesive layer 13 from a two-component curing urethane adhesive, and this laminate was aged at 50 ° C for 3 days to obtain a laminate 1a to build. As the main agent for the adhesive, Takelack A-310 (trademark, manufactured by Takeda Chemical Industries, Ltd., Japan) made of a polyesterurethane polyol and a curing agent A-10 (trademark, Takeda Chemical Industries, Ltd., Japan , prepared) composed of hexamethylene diisocyanate. The adhesive was applied in an amount such that the dried adhesive layer had a thickness of 7 μm.

The [first blackening layer 25A / Metal layer 21 / second corrosion protection layer 23B ] in the laminate 1a were photolithographically converted into a mesh pattern.

Using the existing shadow mask manufacturing equipment for color television sets, the laminate was subjected to a series of steps from masking to etching in the form of a belt-shaped (rolled up) continuous web. First, a photosensitive casein photoresist was applied to the entire surface of the laminate 1a applied by dipping. This laminate was intermittently transported to the next station where ultraviolet light contact exposure of a mercury vapor lamp using a negative pattern plate to form a power supply 103 was performed with line parts with a line width W of 22 microns, a line spacing P (distance) of 300 microns and a skew angle of 49 degrees, the line parts regular square openings 105 define and a 15 mm wide frame part 101 the power supply 103 surrounds. The laminate was then transported from one station to another station for development with water, film hardening treatment and heat treatment by heating. The heat-treated laminate was further transported to the next station where a Etching was performed by spraying an aqueous ferric chloride solution as an etchant over the laminate to openings 105 in the laminate. As the laminate was transferred from one station to the next station, the laminate was washed with water and with an alkaline solution, the photoresist was peeled off and that in the second anticorrosion layer 23B contained zinc was eluted, creating a chromium-containing second corrosion protection layer 23B was obtained. This was washed with water and then dried by heating to form a net.

Example 2

An electromagnetic wave shield sheet was obtained in the same manner as in Example 1, but in the step of forming the anticorrosive layer, both sides of the metal layer became 21 subjected to anticorrosive treatment to obtain a [first anticorrosion layer 23A / first blackening layer 25A / Metal layer 21 / second corrosion protection layer 23B ] to build.

Example 3

The power supply 103 The electromagnetic wave shielding sheet of Example 1 was further subjected to a second blackening treatment. Using a mixture of an aqueous nickel ammonium sulfate solution (60 g / liter), an aqueous zinc sulfate solution (7.5 g / liter) and a sodium thiosulfate aqueous solution (15 g / liter) as a plating bath, the treatment was carried out for 2 minutes under the conditions in that the bath temperature and the current density were 35 ° C and 20 A / cm ² , respectively, around a second blackening layer 25B to build. As a result, a sheet for electromagnetic wave shielding was made 1 obtained in which the front surface (surface), the back surface and the side surfaces of the power supply 103 completely blackened.

Example 4

A shield for electromagnetic waves, in which the front surface, the back surface and the side surfaces of its power supply 103 was completely blackened, was obtained in the same manner as in Example 3 except that the electromagnetic wave shielding sheet of Example 2 was used.

Example 5

A sheet for shielding electromagnetic waves 1 was obtained in the same manner as in Example 1, but in the step of forming the anticorrosive layer, both sides of the metal layer became 21 a tin-nickel alloy plating and also subjected to a chromate treatment to a [first anti-corrosion layer 23A / first blackening layer 25A / Metal layer 21 / second corrosion protection layer 23B ] to build. By eluting tin from the second anticorrosion layer 23B While the photoresist was peeled off, this layer was formed to contain nickel and chromium.

Example 6

A sheet for shielding electromagnetic waves 1 was obtained in the same manner as in Example 2, but in the step of forming the anticorrosive layer, both sides of the metal layer 21 a nickel-zinc alloy plating, a chromate treatment and a Silanhaftvermittlerbehandlung subjected to a [first anti-corrosion layer 23A / first blackening layer 25A / Metal layer 21 / second corrosion protection layer 23B ] to build. By eluting zinc from the second anticorrosion layer 23B While the photoresist was peeled off, this layer was formed to contain nickel, chromium and silicon.

Comparative Example 1

An electromagnetic wave shield sheet was obtained in the same manner as in Example 1, but the anticorrosive layer did not become on the metal layer 21 and formed as the first blackening layer to form [first blackening layer 25A / Metal layer 21 ] formed a black layer of deposited cadmium.

rating

A Review was regarding the corrosion resistance, of non-recognizability and liability.

The corrosion resistance was made electromagnetic by visually inspecting each sheet for shielding Waves rated that a test at high temperature and high humidity at 60 ° C and 95% relative humidity for 1000 hours is. A sheet for shielding electromagnetic waves, whose surface no color change was rated as acceptable and designated "O" rating while a Sheet for shielding electromagnetic waves whose surface is a significant color change was rated as unacceptable and rated "x".

bezeichnet, ein Blatt zur Abschirmung elektromagnetischer Wellen, dessen Netzteil eine Farbänderung aufwies, jedoch in der Praxis unproblematisch erschien, wurde ebenfalls als akzeptabel bewertet und mit der Bewertung „O" bezeichnet, und ein Blatt zur Abschirmung elektromagnetischer Wellen, dessen Netzteil offensichtlich erkennbar war, wurde als nicht akzeptabel bewertet und mit der Bewertung „x" bezeichnet.The unrecognizability was evaluated by visually inspecting the power supply of each sheet for shielding electromagnetic waves to which light was irradiated. An electromagnetic wave shielding sheet whose power supply was undetectable was judged to be acceptable and evaluated

an electromagnetic wave shielding sheet whose power supply had a color change but appeared unproblematic in practice was also judged to be acceptable and rated "O", and an electromagnetic wave shielding sheet whose power supply was obviously recognizable, was rated unacceptable and designated "x".

The Adhesion of the blackening layer was by rubbing the blackened surface with a nonwoven soaked in water and examining whether the blackening layer transferred to the nonwoven fabric has or has not been evaluated. A sheet for shielding electromagnetic Waves, its blackening layer transferred to the nonwoven fabric so that she blackened the fleece was considered unacceptable rated and labeled "x", a sheet for shielding electromagnetic waves, whose blackening layer hardly recognizable discolored has been assessed as acceptable and designated as "O", and a sheet for shielding electromagnetic waves, its blackening layer discolored became, which appeared however without problem in practice, became also rated as acceptable and labeled "Δ".

review results

The Evaluation results are shown in Table 1.

Table 1

The electromagnetic wave shielding sheets of Examples 1 to 6 were evaluated as acceptable with respect to each evaluation item. The electromagnetic wave shielding sheet of Comparative Example 1 was judged to be acceptable in adhesion to the blackening layer, however evaluated as unacceptable in terms of corrosion resistance. In addition, the blackening layer partially dissolved in the intermediate step. Since such sections reflect light, the power supply appeared partially shiny, making this blade unacceptable for shielding electromagnetic waves.

Further was the effect of shielding electromagnetic waves with the KEC procedure (A method for measuring electromagnetic waves, that of Kansai Electronic Industry Development Center, Japan is) determined. All leaves for shielding electromagnetic waves of Examples 1 to 6 and Comparative Example 1 attenuated electromagnetic waves with frequencies from 30 MHz to 1000 MHz at rates of 30 to 60 dB and it has therefore been confirmed that they have satisfactorily excellent shielding properties had electromagnetic waves.

Summary

A sheet for shielding electromagnetic waves 1 comprises a transparent substrate 11 and a first anti-corrosion layer 23A , a first blackening layer 25A a metal layer 21 and a second corrosion protection layer 23B successively on the transparent substrate 11 by means of an adhesive layer 13 are formed. A second blackening layer 25B is designed to cover the side surfaces of the first anticorrosion layer 23A , the first blackening layer 25A , the metal layer 21 and the second anticorrosion layer 23B and the front surface of the second anticorrosion layer 23B completely covered. At least one of the first corrosion protection layer 23A and the second anticorrosion layer 23B contains one or more metals selected from nickel, chromium and silicon, and also zinc and / or tin when initially formed, and the zinc and / or tin is selected from the group consisting of first corrosion protection layer 23A and / or the second corrosion protection layer 23B removed in an intermediate step. ( 3 )

Claims (8)

Sheet for shielding electromagnetic waves, the a transparent substrate and one with an adhesive layer on a surface of the transparent substrate laminated metal mesh layer, a first, copper-containing blackening layer, the one on a surface the metal mesh layer on the side of the transparent substrate is formed, and a second anticorrosive layer containing a or contains more metal (s), which is selected from chromium, nickel and silicon and are on the other surface of the metal mesh layer opposite the page the transparent substrate is formed comprises. Sheet for shielding electromagnetic waves according to claim 1, further comprising a first anticorrosion layer, containing one or more metal (s) made of chromium, Nickel and silicon selected is, and that between the first blackening layer and the transparent Substrate is formed. Sheet for shielding electromagnetic waves according to claim 1, wherein the side surfaces of the first blackening layer, the metal layer and the second anticorrosive layer on the transparent substrate, and the front surface of the second anticorrosion layer completely with a second blackening layer are covered. Sheet for shielding electromagnetic waves according to claim 2, in which the side surfaces of the first anticorrosion layer, the first blackening layer, the metal layer and the second anticorrosive layer on the transparent substrate, and the front surface of the second anticorrosion layer completely with a second blackening layer are covered. Sheet for shielding electromagnetic waves according to claim 3 or 4, wherein the second blackening layer is by plating has been formed and at least one metal made of copper, Cobalt, nickel, zinc, molybdenum, Tin and chrome selected is, or a compound of any of these metals or an alloy, which consists of two or more of these metals includes. A method of producing an electromagnetic wave shielding sheet comprising the steps of forming a metal layer, sequentially forming a first blackening layer and a first anti-corrosion layer on the surface of the metal layer on the side of a transparent substrate, forming a second anti-corrosion layer on the other surface the metal layer on the side ge over the transparent substrate, laminating the metal layer and the transparent substrate with an adhesive layer, the first anti-corrosion layer facing the transparent substrate, forming a laminate, and etching the laminate to form the metal layer into a mesh. Method for producing a sheet for shielding Electromagnetic waves according to claim 6, wherein at least one the first corrosion protection layer and the second corrosion protection layer contains one or more metal (s), nickel, chromium and silicon, and also zinc and / or Tin, if it is initial is formed, selected is or, and the zinc and / or tin from the first corrosion protection layer and / or the second anticorrosion layer in the step of etching becomes. Method for producing a sheet for shielding Electromagnetic waves according to claim 6, wherein after step of the etching the side surfaces the first anti-corrosion layer, the first blackening layer, the metal layer and the second anticorrosion layer used in the laminate, and the front surface of the second anticorrosion layer Completely with a second blackening layer to be covered.