JP2009076827A - Near-infrared ray, laminate for electromagnetic wave shielding, and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide near-infrared ray and electromagnetic wave shielding laminate which are excellent in near-infrared ray shielding, visible light transmittance, and electromagnetic wave shielding, and which can be easily manufactured at low cost. <P>SOLUTION: A transparent base material is coated with a coating liquid containing tungsten-oxide-based or phthalocyanine-based near-infrared rays absorbent, a binder resin, and a solvent in which they are dissolved or dispersed, and is then dried to form a near-infrared ray shielding layer 4. A conductive paste 21 is directly printed thereon in a mesh-state by using, for example, a gravure direct printing machine, and a mesh-like electromagnetic wave shielding layer is formed thereon by applying electrolytic plating thereto, to manufacture the near-infrared ray and electromagnetic wave shielding laminate. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical filter mounted on a plasma display or the like, a near-infrared / electromagnetic wave shielding laminate that can be suitably used for windows of buildings and vehicles, and a manufacturing method thereof. More specifically, the present invention is an inexpensive near-infrared / electromagnetic wave shielding laminate having excellent near-infrared shielding properties, visible light transmission properties, and electromagnetic wave shielding properties, and near-infrared rays having the above properties. The present invention relates to a method for producing a near-infrared / electromagnetic wave shielding laminate capable of inexpensively producing an electromagnetic shielding laminate by a simple production process.

  For example, a plasma display device generally includes a near-infrared / electromagnetic wave shielding laminate having a near-infrared shielding layer and an electromagnetic wave shielding layer for shielding near-infrared rays and electromagnetic waves generated from the display device on a glass in front of a light emitting module. An optical filter including the body is installed. In addition, the optical filter often includes means for imparting antireflection properties in order to improve functions other than near-infrared shielding and electromagnetic wave shielding, for example, visibility.

  Cost reduction is important for the spread of consumer-use plasma display televisions, and the cost reduction of optical filters is also required. An optical filter generally includes an electromagnetic wave shielding film in which an electromagnetic wave shielding layer is laminated on a transparent film, a near infrared ray shielding film in which a near infrared ray shielding layer is laminated on a transparent film, and an antireflection layer on the transparent film. Since a plurality of various functional films including a laminated antireflection film are manufactured together, there are many manufacturing processes, low productivity, and high manufacturing costs.

  The electromagnetic shielding layer generally uses an etching mesh film formed in a lattice shape by etching a copper foil formed on a transparent film by a photolithography process. However, in the production of the etching mesh film, a patterned resist resin film is formed on the copper foil laminated on the transparent film, and this copper foil is etched to form a mesh pattern copper foil layer. Since the method is used, there are problems that the process is complicated, the material used is wasted, and the manufacturing cost is high. In addition, since it is difficult to manage the etching conditions, there is a problem that the manufacturing yield is low and the manufacturing cost is further increased.

  Therefore, in order to solve the above-mentioned problems relating to manufacturing cost and productivity, attempts have been made to laminate an electromagnetic wave shielding layer and a near infrared shielding layer on a single transparent film. In Japanese Patent No. 313918 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2006-243757 (Patent Document 2), a metal such as silver and a metal oxide such as tin-containing indium oxide are alternately stacked to form a film. Thus, a near infrared / electromagnetic wave shielding laminate having both near infrared shielding ability and electromagnetic shielding ability is disclosed. Japanese Patent Laid-Open No. 2002-3118433 (Patent Document 3) contains an organic absorbent that absorbs a specific wavelength of visible light and / or near infrared in a mesh made of a metal thin film formed by an etching method. A laminated body for near-infrared / electromagnetic wave shielding produced by laminating on a transparent film via an adhesive or pressure-sensitive adhesive that has both near-infrared shielding ability and electromagnetic shielding ability is disclosed.

However, in the case of the methods of Patent Documents 1 and 2, the sputtering apparatus requires a large-scale vacuum facility, so that the manufacturing cost is high, and the electromagnetic wave shielding ability and the near infrared shielding performance required for the plasma display are sufficient. In order to obtain it, since it is necessary to laminate | stack the electromagnetic wave shielding layer and a near-infrared shielding layer in the multilayer of 7-9 layers or more, there exists a problem that it is difficult to fully reduce manufacturing cost.
Further, in the case of the method of Patent Document 3, since a mesh made of a metal thin film is formed by using an etching method, the manufacturing cost of the mesh itself increases, and a sufficient cost reduction and simplification of the manufacturing process cannot be expected.

Therefore, as a method for inexpensively producing a near-infrared / electromagnetic wave shielding laminate having both a near-infrared shielding ability and an electromagnetic shielding ability by laminating a near-infrared shielding layer and an electromagnetic shielding layer on a single transparent film. A method of forming a metal mesh film on the near-infrared shielding layer formed on the surface of the transparent film by electroplating using a printing method that is excellent in mass productivity and inexpensive can be considered. In the case of the plating process, in order to ensure good printability and adhesion, a receiving layer of the conductive paste is required as a base. Therefore, if the receiving layer can contain a near-infrared absorber, Compounding is possible without increasing the number of processes, and significant cost reductions can be expected.
However, conventionally, organic dyes such as imoniums have been used for near-infrared absorbers, but because these organic dyes have low acid resistance and alkali resistance, printing of conductive paste, electroplating treatment, etc. In the organic resin suitable for the formation of the receiving layer, organic dyes such as imonium are easily deteriorated and deteriorated, and for this reason, a mesh made of a metal thin film is formed on the near infrared shielding layer. It was difficult to form by electrolytic plating using a printing method.

JP 2006-313918 A JP 2006-243757 A JP 2002-311843 A

  The present invention is a near-infrared / electromagnetic wave shielding laminate having the above-mentioned properties, which has excellent near-infrared shielding properties and visible light transmission properties, and is also excellent in electromagnetic wave shielding properties, and an inexpensive near-infrared / electromagnetic wave shielding laminate. It is an object of the present invention to provide a method for producing a near-infrared / electromagnetic wave shielding laminate capable of inexpensively producing a laminate for use in a simple process.

  As a result of intensive investigations for solving the above problems, the present inventor has achieved excellent productivity and inexpensive printing on the near-infrared shielding layer formed on the surface of the transparent film by using a specific near-infrared absorber. It is possible to form a metal mesh film by electroplating using this method, and it has excellent near-infrared shielding properties, visible light transmission properties, and electromagnetic wave shielding properties without increasing special processes. It has been found that a laminate for shielding infrared rays and electromagnetic waves can be produced at a low cost, and the present invention has been completed.

That is, the near infrared / electromagnetic wave shielding laminate of the present invention comprises a transparent substrate, a near infrared shielding layer formed on one main surface of the transparent substrate, and an electromagnetic wave formed on the near infrared shielding layer. A near infrared / electromagnetic wave shielding laminate in which a shielding metal mesh layer is laminated and integrated,
The near-infrared shielding layer contains at least one selected from tungsten oxide-based and phthalocyanine-based near infrared absorbers, and a binder resin.
The electromagnetic shielding metal mesh layer is formed by performing electrolytic plating on a mesh-like conductive pattern layer formed on the near-infrared shielding layer.
In addition, the method for producing a near-infrared / electromagnetic wave shielding laminate of the present invention comprises, on one main surface of a transparent substrate, at least one selected from tungsten oxide-based and phthalocyanine-based near-infrared absorbers, and a binder. Applying a near-infrared shielding composition containing a resin and a solvent that dissolves or disperses the near-infrared absorber and the binder resin, and drying to form a near-infrared shielding layer; and on the near-infrared shielding layer In addition, a conductive paste containing conductive particles is printed in a mesh shape to form a conductive pattern layer, and an electroplating is performed on the mesh conductive pattern layer to form an electromagnetic wave shielding metal mesh layer. And a metal mesh layer forming step for electromagnetic wave shielding including the step.
In the manufacturing method of the near infrared / electromagnetic wave shielding laminate of the present invention, it is preferable that the conductive paste is printed using a gravure printing method in the electromagnetic shielding metal mesh layer forming step.
In the manufacturing method of the near infrared / electromagnetic wave shielding laminate of the present invention, the conductive paste printing by the gravure printing method fills the grooves formed in the mesh pattern on the gravure printing plate cylinder with the conductive paste. Further, a near infrared ray shielding layer on the transparent substrate is pressure-bonded thereon for a predetermined time, so that the conductive paste on the plate cylinder is transferred to the near infrared ray without using a transfer sheet (blanket). It is preferably applied by direct transfer onto the absorbent layer.
In the method for producing a near-infrared / electromagnetic wave shielding laminate of the present invention, it is preferable that the predetermined pressure bonding time in the transfer of the conductive paste is 0.5 seconds to 10 seconds.

"Laminated body for near infrared and electromagnetic wave shielding"
FIG. 1 shows an embodiment (1) of the near infrared / electromagnetic wave shielding laminate of the present invention. In FIG. 1, the near-infrared electromagnetic wave shielding laminate 10 includes a transparent base material 2, a near-infrared shielding layer 4 formed on the transparent base material 2, and an electromagnetic shielding material formed on the near-infrared shielding layer 4. A metal mesh layer 3 is provided, and these layers 2, 3 and 4 are laminated in an integral sheet shape.

  Further, in FIG. 1, the near-infrared shielding layer 4 is formed of at least one tungsten oxide-based and phthalocyanine-based near-infrared absorber and a binder resin, and the electromagnetic shielding metal mesh layer 3 is As schematically shown in FIG. 2, an electrolytic plating layer 22 is formed on the conductive pattern layer 21 formed on the near-infrared shielding layer 4.

  The near-infrared absorber has a high resistance to chemicals, particularly a conductive paste containing conductive particles and an electroplating bath, and has a near 850 nm to 1000 nm required for a plasma display. Excellent shielding ability in the infrared region and transparency in the visible light region.

Examples of the tungsten oxide-based near-infrared absorber having the above-described characteristics include, for example, a general formula: W _y O _z [W represents a tungsten atom, O represents an oxygen atom, and 2.2 ≦ z / y. ≦ 2.999] and fine particles of tungsten oxide represented by the general formula: M _x W _y O _z [where M is H, He, alkali metal, alkaline earth metal, rare earth element, Mg, Zr, Cr, Mn, Fe, Ru, Co, Rh, Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, Al, Ga, In, Tl, Si, Ge, Sn, Pb, Sb, B, Represents one or more atoms selected from the group consisting of F, P, S, Se, Br, Te, Ti, Nb, V, Mo, Ta, Re, Be, Hf, Os, Bi, and I; Represents a tungsten atom, O represents an oxygen atom, and 0.001 ≦ x y ≦ 1.1,2.2 ≦ z / y ≦ 3.0, when x is plural, the plurality of M, may be mutually different, or may be homologous. The tungsten oxide type near-infrared absorber can be appropriately selected from commercially available ones and used.

When using a tungsten oxide-based near infrared absorber as the near infrared absorber, the content in the near infrared shielding layer is not particularly limited, but in order to obtain good near infrared shielding properties and visible light transmittance, it is preferably in the range of 0.5 to 5 g / m ^2, more preferably 1 to 3 g / m ^2. The content of the near-infrared absorbing material of the tungsten oxide is lower than 0.5 g / m ² near-infrared region without sufficient shielding ability is obtained, than 5 g / m ² Conversely, high and in the visible light region The transmittance is significantly reduced.
The average particle size of the tungsten oxide-based near-infrared absorber is preferably 0.01 μm to 0.1 μm from the viewpoints of near-infrared shielding, transparency, and coatability. Moreover, it is preferable that the near-infrared absorber of tungsten oxide is dispersed so that the dispersed particle diameter is 0.1 μm or less in the near-infrared shielding layer from the viewpoint of transparency.

Examples of the phthalocyanine-based near-infrared absorber having the above-described properties include those selected from compounds represented by the following general formula (I), and commercially available ones are preferably used. be able to.
In the general formula (I), eight α's each independently represent one member selected from —SR ¹ , —OR ² and —NHR ³ groups and a halogen atom, provided that at least one α represents an —NHR ³ group, and eight βs each independently represent at least one member selected from —SR ¹ , —OR ² and a halogen atom, provided that at least one β is , -SR ¹ or -OR ² group, and at least one of the 8 α and β represents a halogen atom and -OR ² group,
R ¹ , R ² and R ³ each independently represent a phenyl group having or not having a substituent, an alkyl group having 1 to 20 carbon atoms, and 7 to 20 carbon atoms. Represents a member selected from the aralkyl groups possessed,
M represents one member selected from one metal atom, one or more hydrogen atoms, one metal oxide, and a metal halide.

When using organic dyes of phthalocyanines as near-infrared absorbers, phthalocyanines often have an absorption peak at a specific wavelength in the near-infrared region. It is necessary to select the kind of class. In order to sufficiently shield the wavelength of 850 nm to 1000 nm required for the plasma display, it is preferable to use two or more kinds of phthalocyanines together.
Although there is no restriction | limiting in particular in content of the phthalocyanines contained in a near-infrared shielding layer, In order to obtain a favorable near-infrared shielding characteristic and visible light transmittance, it exists in the range of 0.01-2 g / m < ² >. It is preferably 0.1 to 1 g / m ² . If the content is lower than 0.01 g / m ² , sufficient shielding ability in the near infrared region may not be obtained. Conversely, if the content is higher than 2 g / m ² , the transmittance in the visible light region may be low. May decrease significantly.

  As the near-infrared absorber, the above-described tungsten oxide-based near infrared absorber and phthalocyanine-based near infrared absorber may be used in combination. The content and blending ratio in the case of using a tungsten oxide-based near infrared absorber and a phthalocyanine-based near infrared absorber in combination can be appropriately set so as to obtain a desired near-infrared shielding ability and visible light transmittance, What is necessary is just to adjust suitably according to desired performance.

  As the binder resin for the near-infrared shielding layer, it is preferable to use a resin having high chemical resistance, in particular, a conductive paste containing conductive particles and a resin having high resistance to an electrolytic plating bath, for example, ethyl cellulose, One or more kinds of cellulose derivatives such as propyl cellulose, polyvinyl butyral resin, acrylic resin, polyurethane resin, and rosin ester resin can be used, and two or more kinds may be mixed.

  In addition, as the binder resin, it is particularly preferable to use a resin having moderate flexibility such as a polyvinyl butyral resin. When the near-infrared shielding layer has an appropriate flexibility, in gravure printing suitably used in the following production method of the present invention, when the conductive paste is transferred from the body plate onto the near-infrared shielding layer, the near-infrared shielding is performed. Since the layer can sufficiently follow the image portion (groove) of the body plate and can enter the groove, transferability is also improved.

In FIG. 2, the near-infrared shielding layer 4 preferably has a function as a receiving layer when printing a conductive paste, as described above, and the dripping of the conductive pattern layer 21 printed according to a predetermined pattern, It is necessary to prevent bleeding and improve the adhesion strength between the near-infrared shielding layer 4 and the printed conductive pattern layer 21. Therefore, it is preferable to add oxide fine particles (hereinafter sometimes referred to as “conductive fine particle for accepting conductive paste”) in order to enhance the performance as a receiving layer when printing the conductive paste. . Examples of such conductive paste-accepting oxide fine particles include alumina (Al ₂ O ₃ ), silica (SiO ₂ ), titania (TiO ₂ ), zirconia (ZrO ₂ ), and two or more types. These oxide fine particles may be mixed and used. These conductive paste receiving oxide fine particles preferably have an average particle size of 0.01 μm to 5 μm, more preferably conductive paste receiving oxide fine particles having an average particle size of 0.01 μm to 0.1 μm. It is preferable to use and disperse in the near-infrared shielding layer 4 so that the dispersed particle diameter is 0.1 μm or less because the transparency and adhesion of the obtained near-infrared shielding layer 4 are improved.
The content of the conductive paste-receiving oxide fine particles in the near-infrared shielding layer 4 is preferably 50% by weight or less. If it exceeds 50% by weight, the transparency of the near-infrared shielding layer 4 is lowered, which is not preferable.

  In the near-infrared shielding layer, the blending ratio of the filler (representing a near-infrared absorber or a mixture of the near-infrared absorber and the conductive paste-receiving oxide fine particles) and the binder resin is 90/10 to 10 in terms of mass ratio. When the ratio of the filler is higher than 90/10, the adhesion strength between the transparent base material 1 and the near-infrared shielding layer 4 is weakened, and the transmittance is lowered and the haze value is high. May be. On the contrary, if the ratio of the filler is lower than 10/90, the adhesion strength becomes weak and the effect as the receiving layer of the conductive paste is reduced. When the conductive paste layer 21 is formed, it sags, bleeds, etc. May occur.

  Moreover, it is preferable that the thickness of a near-infrared shielding layer is 0.5-5 micrometers, More preferably, it is 1-3 micrometers. If the near-infrared shielding layer is thinner than 0.5 μm, the effect of the conductive paste as a receiving layer may be insufficient. If the near-infrared shielding layer is thicker than 5 μm, the conductive paste May crack in the layer.

In the near-infrared / electromagnetic wave shielding laminate of the present invention, examples of the transparent substrate include transparent plastic, transparent plastic board, and glass.
As the material of the transparent plastic and the transparent plastic board, from the viewpoint of optical properties and mechanical properties, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, terephthalic acid-isophthalic acid-ethylene glycol copolymer, terephthalic acid- Polyester resins such as cyclohexanedimethanol-ethylene glycol copolymer, polyamide resins such as nylon 6, polyolefin resins such as polypropylene and polymethylpentene, acrylic resins such as polymethyl methacrylate, polystyrene, styrene-acrylonitrile copolymer It is preferable to use a styrene resin such as coalescence, a cellulose resin such as triacetyl cellulose, an imide resin, or a polycarbonate resin.

The electroconductive pattern layer containing electroconductive particle is comprised with the composite material containing electroconductive particle, organic polymer resin, and the black pigment and thixotropic agent added as needed.
The conductive particles are added to impart conductivity so that electrolytic plating is possible. Examples of such conductive particles include silver (Ag), palladium (Pd), and platinum (Pt). , A metal or alloy containing an element selected from gold (Au), ruthenium (Ru), copper (Cu), nickel (Ni), silver oxide (Ag ₂ O), palladium oxide (PdO), ruthenium oxide ( Examples thereof include conductive metal oxide fine particles such as RuO ₂ ). Two or more kinds of these conductive particles may be mixed and used.

The thixotropic agent is added to improve the printability of the conductive paste. Examples of the thixotropic agent include oxide fine particles having a large oil absorption amount, bentonite soluble in organic solvents, and smectite. Examples thereof include clay minerals such as organic thixotropic agents. Here, the amount of oil absorption refers to a value measured in accordance with JIS-K5101 using a solvent in a conductive paste containing oxide fine particles.
Examples of the oxide fine particles having a large oil absorption include metal oxide fine particles such as alumina (Al ₂ O ₃ ), zinc oxide (ZnO), zirconia (ZrO ₂ ), and titania (TiO ₂ ). Two or more kinds of these metal oxide fine particles may be mixed and used.

The black pigment is added as necessary to blacken the bottom surface of the electromagnetic wave shielding film having a predetermined pattern in order to improve contrast. Examples of such a black pigment include carbon black.
The black pigment content is preferably 0.03% by mass to 3.0% by mass, more preferably 0.1% by mass to 1.0% by mass. When the content of the black pigment is less than 0.03% by mass, the blackness of the mesh on the back surface of the conductive pattern layer 21 is insufficient, and when mounted on the display surface of a display such as a PDP, good contrast cannot be obtained. On the other hand, if it exceeds 3.0 mass%, the blackness of the mesh on the back surface of the conductive pattern layer 21 will be good and good contrast will be obtained, but the printability will be poor.

  The organic polymer resin may be any resin that is suitable for gravure printing and resistant to electrolytic plating solution, and examples thereof include ethyl cellulose, rosin ester resin, acrylic resin, polyvinyl butyral resin, and polyurethane resin. Two or more kinds of these resins may be mixed and used.

  Further, the ratio (NM / R) between the conductive particles (NM) and the organic polymer resin (R) is preferably 40/60 to 80/20, more preferably 60/40 to 70/30 in mass ratio. It is. If the ratio of the conductive particles is lower than the above range, the conductive particles are almost covered with the organic polymer resin, and a surface resistance value (50Ω / □ or less) that enables electrolytic plating cannot be obtained. On the other hand, if it is higher than the above range, the printability is deteriorated, and the conductive pattern layer is not sufficiently cured by the organic polymer resin, and the adhesiveness to the transparent substrate cannot be obtained.

  The shape of the mesh porosity of the conductive paste layer of the mesh pattern is not limited, for example, a triangle including a regular triangle, an isosceles triangle, a right triangle, a square, a rectangle, a parallelogram, a rhombus, Other polygons including trapezoids, rectangles, hexagons, octagons, dodecagons, etc., circles, ellipses, etc., any one of these repeating patterns, or these two It can also be configured by combining more than one species.

On the mesh-shaped conductive pattern layer, electrolytic plating is performed by electrolytic plating to form an electrolytic metal plating layer. Examples of the metal constituting the electrolytic plating layer include copper (Cu) and nickel (Ni).
The total thickness of the conductive pattern layer and the electrolytic plating layer is preferably 30 μm or less, and more preferably 1 μm or more and 5 μm or less.
The outermost surface portion of the electromagnetic shielding metal mesh layer 3 is preferably a black layer in order to suppress the reflection of visible light and increase the contrast to improve the visibility.

  In the mesh structure composed of the metal wires of the conductive electromagnetic wave shielding mesh layer, the interval (S) between the metal wires is usually about 100 to 500 μm, and the metal line width (L) is usually about 10 to 80 μm. Preferably, the line spacing (S) is about 125 to 500 μm, and the line width (L) is about 10 to 40 μm. When the distance (S) between the metal lines is larger than 500 μm, the mesh pattern tends to be noticeable and the visibility of the display screen tends to be lowered. On the other hand, when the spacing is smaller than 100 μm, the mesh pattern is fine. As a result, the transmittance of visible light is lowered, and the display screen tends to be darkened.

  Further, if the metal line width (L) exceeds about 80 μm, the mesh pattern tends to be noticeable and the visibility of the display screen tends to decrease, and the metal line width (L) is less than about 10 μm. Since the form tends to be difficult, the metal line width (L) is preferably 10 μm or more and 80 μm or less. The thickness of the metal wire is preferably about 1 μm or more, but is usually preferably about 30 μm or less. If the thickness of the metal wire is less than about 1 μm, electromagnetic wave shielding may be insufficient, and if the line spacing is adjusted to make the brightness (light transmittance) the same, printing becomes difficult. It is preferable to set the metal line width (L) to about 40 μm or less and to narrow the metal line interval (S) because the electromagnetic wave shielding ability is increased. In the case of a pattern other than a square, the line spacing is a value converted to a square, and this is obtained from the measured values of the metal line width and light transmittance.

If necessary, a functional layer 5 may be laminated on the electromagnetic wave shielding mesh layer 3 via an adhesive layer 6 as shown in FIG. In order to provide the near-infrared / electromagnetic wave shielding laminate 10 with other functions that cannot be realized from the above-described layer configuration, such as improvement of the optical properties of the shielding laminate 10, protection function, and improvement of mechanical strength. belongs to. Specific examples of the functional layer 5 include known functional layers such as an antireflection functional layer, an antiglare functional layer, a neon light shielding functional layer, an ultraviolet absorbing functional layer, and a hard coat layer for preventing scratches. Can do.
In addition, the said functional layer 5 is laminated | stacked through the adhesion layer 6 on the back surface of the said transparent base material 1, ie, the other main surface of the transparent base material 1 where the near-infrared shielding layer 4 is not laminated | stacked. It may be.

There is no restriction | limiting in particular in the adhesive which comprises the said adhesion layer 6, Although it has moderate adhesiveness, transparency, applicability | paintability from what is conventionally used as a well-known adhesive, tungsten oxide type and / or Those that react with the phthalocyanine-based near-infrared absorber and do not affect the transmission spectrum in the near-infrared and visible light regions can be appropriately selected and used.
Examples of such pressure-sensitive adhesives include acrylic pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, and polyester-based pressure-sensitive adhesives, and acrylic pressure-sensitive adhesives having good light resistance are particularly preferable.

  Because the near infrared / electromagnetic wave shielding laminate having the above-described configuration uses a tungsten oxide-based and / or phthalocyanine-based near infrared absorber having excellent acid resistance and alkali resistance as a near infrared absorber. In the near-infrared shielding property and the visible light transmittance, the transmittance in the near-infrared region of 850 nm to 1000 nm is 10% or less without being deteriorated by processes such as conductive paste printing and electrolytic plating treatment. It has excellent performance with a transmittance of 40% or more, and also has an electromagnetic shielding performance at 30 to 1000 MHz with an excellent performance of 50 dB or more, and also has an excellent low price. It can be suitably used as an optical filter mounted on a display or the like.

"Production method of near infrared / electromagnetic wave shielding laminate"
The method of the present invention for producing the near infrared / electromagnetic wave shielding laminate of the present invention comprises, on one main surface of a transparent substrate, a tungsten oxide-based and / or phthalocyanine-based near-infrared absorber, a binder resin, Applying a near-infrared shielding composition containing the near-infrared absorber and a solvent for dissolving or dispersing the binder resin, drying the coating film, and laminating a near-infrared shielding layer, and this near-infrared ray On the shielding layer, a conductive paste containing conductive particles is printed in a mesh shape, dried as necessary to form a conductive pattern, and this mesh-shaped conductive pattern is subjected to electroplating to provide a mesh-shaped electrolysis. An electromagnetic wave shielding metal mesh layer forming step of forming a plating layer.

Hereinafter, the manufacturing method of the near infrared / electromagnetic wave shielding laminate will be described in detail for each step.
Preparation of near-infrared shielding composition Tungsten oxide-based and / or phthalocyanine-based near-infrared absorber, binder resin, and if necessary, conductive paste-accepting oxide fine particles, the above-mentioned near-infrared absorber, binder A near-infrared shielding composition is prepared by mixing a resin and a conductive paste-receiving oxide fine particle in a solvent in which the resin is dissolved or dispersed.
The mixing method is not particularly limited, and various conventionally known mixing methods can be appropriately selected and employed.

There is no particular limitation on the addition amount of one or more of the tungsten oxide-based and phthalocyanine-based near infrared absorbers, the binder resin, and the conductive paste-receiving oxide fine particles in the near-infrared shielding composition. What is necessary is just to set suitably so that the near-infrared shielding layer of a desired characteristic may be obtained.
Solvents used in the near-infrared shielding composition include aromatic solvents such as toluene and xylene, cyclized aliphatic solvents such as cyclohexanone, ketone solvents such as methyl ethyl ketone (MEK), and alcohol solvents such as isopropyl alcohol. There is no particular limitation as long as it can dissolve or disperse the near-infrared absorber, binder resin, and conductive paste-receiving oxide fine particles. In order to facilitate the dispersion of the conductive paste-receiving oxide fine particles, a phosphate ester-based dispersant or the like may be added.

Formation of near-infrared shielding layer The near-infrared shielding composition is applied onto one main surface of a transparent substrate, and the coating film is dried to form and laminate a near-infrared shielding layer on one main surface of the transparent substrate. .

As a coating method for applying the near-infrared shielding composition on one main surface of the transparent substrate, conventionally known coating methods such as gravure printing, bar coating printing, and offset printing can be employed.
The method for drying the coating film is not particularly limited, and it is preferable to dry until the amount of the solvent remaining in the near-infrared shielding layer is 3% by mass or less, preferably 1% by mass or less. If the amount of solvent remaining in the near-infrared shielding layer exceeds 3% by mass, long-term near-infrared shielding properties may be deteriorated.

Formation of Conductive Pattern Layer A conductive pattern layer is formed by applying a conductive paste in a predetermined pattern on the above-mentioned near-infrared shielding layer by gravure printing and heat-treating it.
As the conductive paste, a paste containing conductive particles, an organic polymer resin, an organic solvent, and a black pigment or thixotropic agent added as necessary is suitably used.

The average particle diameter of the conductive particles is preferably 0.001 μm to 5 μm, more preferably 0.001 μm to 2 μm. If the average particle size of the conductive particles is less than 0.01 μm, sufficient conductivity cannot be obtained. On the other hand, if the average particle size exceeds 5 μm, it may be difficult to print fine lines.
The amount of solid content in the conductive paste is not particularly limited, and for example, 30 to 90% by mass is preferable from the viewpoint of coatability.

  As the organic solvent, an organic polymer resin can be dissolved or dispersed, and it may be suitable for gravure printing. For example, toluene, methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), butyl acetate, cyclohexanone, butyl carbide. Tolu, butyl carbitol acetate, α-terpineol and the like can be mentioned.

The viscosity of this conductive paste is preferably 1 to 500 Pa · s, more preferably 50 to 200 Pa · s.
This is because if the viscosity of the conductive paste is less than 1 Pa · s, the thixtopy property of the conductive paste is lost, and defects such as stringing occur, and a good printed shape cannot be obtained. If s is exceeded, the conductive paste cannot be supplied during gravure printing, and printing unevenness occurs.

  As a method for printing the conductive paste in a mesh form on the near infrared shielding layer, it is preferable to use a gravure printing method, and the conductive paste on the plate cylinder for gravure printing is applied to the transparent substrate. It is preferable to use a method of transferring the conductive paste to the near-infrared absorbing layer 4 by pressing the near-infrared shielding layer 4 for 0.5 to 10 seconds, for example, a gravure direct printing method.

  FIG. 3 is an explanatory diagram for explaining an outline of such a gravure direct printing method. In FIG. 3, the gravure direct printing machine 30 includes a first backup roll 31, a gravure printing plate 32, a doctor blade 33, and a second backup roll 34. By adjusting the positions of the first and second backup rolls 31 and 34 according to the printing speed so as to obtain a constant pressure bonding time, the gravure printing plate 32 can be used without using a transfer sheet (that is, a blanket). The conductive paste layer 38 can be formed directly on the near infrared shielding layer 35 on the transparent substrate by transferring the conductive paste 36 to the mesh pattern.

  If the pressure-bonding time is shorter than 0.5 seconds, the absorption of the solvent into the near-infrared shielding layer is insufficient, and the viscosity of the conductive paste filled in the ink groove of the printing plate is not increased, and the stringing is performed. Etc. may occur and a good printed shape may not be obtained. If the pressure bonding time is longer than 10 seconds, the solvent is excessively absorbed, the viscosity of the conductive paste becomes too high, and it may be difficult to transfer the conductive paste onto the near infrared shielding layer.

By adopting such a gravure direct printing method, the transferability and transfer rate of the conductive paste to the near-infrared shielding layer are improved.
Also, by adjusting the depth of the groove of the gravure printing plate, it becomes possible to print a thicker conductive paste layer compared to normal gravure printing using a blanket. Metal deposition is facilitated.
Furthermore, since the conductive paste is transferred without using a transfer sheet (that is, a blanket), a mesh-like pattern in which lattice lines constituting the mesh are continuous can be formed, and the production yield of the product can be increased. improves.

In addition, according to such a gravure direct printing method, the gravure plate and the near-infrared shielding layer are pressure-bonded for a certain period of time, so that the solvent in the conductive paste filled in the groove of the gravure printing plate is a receiving layer. Absorbed in the infrared shielding layer, the viscosity of the conductive paste suddenly increases, so the conductive paste filled in the groove is transferred to the near infrared shielding layer while maintaining the image shape of the gravure printing plate. Is done.
In addition, the solvent absorbed in the near-infrared shielding layer temporarily dissolves the binder resin on the surface of the near-infrared shielding layer, and this dissolved binder resin layer and the printed conductive paste layer are compatible at the interface, The adhesion strength between the near-infrared shielding layer and the conductive paste layer after drying is increased. When drying after printing, it is preferable to carry out at 100 ° C. or less in consideration of dry cracking of the printed conductive paste layer.

  By adopting such a gravure direct printing method, a fine mesh pattern having a line width (L) of about 10 to 20 μm is maintained at high speed, for example, at a high speed of about 30 m / min, and the designed image shape is accurately maintained. As it is, it can be printed on the near-infrared shielding layer.

Formation of Electrolytic Metal Plating Layer Electrolytic plating is performed on the mesh-like conductive paste layer to form an electrolytic metal plating layer, further improving the conductivity of the electromagnetic shielding layer and enhancing its electromagnetic shielding effect.
As an electrolytic plating method, a conventionally known electrolytic plating method can be adopted. As a metal deposited on the conductive paste layer, for example, copper or nickel is used, and electrolytic metal plating excellent in conductivity and durability is used. A layer can be formed.

The outermost surface portion of the electromagnetic shielding metal mesh layer manufactured by the above-described method is preferably a black layer in order to suppress the reflection of visible light and increase the contrast to improve the visibility. In order to form a black layer on the outermost surface portion, a method of covering with a black metal layer or a black electrodeposition layer, a blackening method by oxidation or sulfuration treatment, or the like can be employed.
To coat with a black metal layer, for example, black nickel plating treatment or chromate plating treatment, black ternary alloy plating treatment using tin, nickel and copper, black ternary alloy plating treatment using tin, nickel and molybdenum, etc. That's fine.

  The black electrodeposition layer is a black layer provided by electrodeposition, and can be formed, for example, by electrodeposition using a black paint in which a black pigment is dispersed in an electrodeposition resin. it can. Examples of the black pigment include carbon black, and it is preferable to use a conductive black pigment. The electrodeposition resin may be an anionic resin or a cationic resin, and specifically, an acrylic resin, a polyester resin, an epoxy resin, etc., these electrodeposition resins are respectively It can be used alone or in combination of two or more. Furthermore, the metal surface can be blackened by oxidation treatment or sulfuration treatment. The oxidation treatment and sulfurization treatment for blackening can be performed by known methods, respectively.

  According to the method for producing a near-infrared / electromagnetic wave shielding laminate of the present invention, as a near-infrared absorber, a tungsten oxide-based and / or phthalocyanine-based near-infrared absorber excellent in acid resistance and alkali resistance is used. The metal mesh film can be formed with a fine pattern as designed by electrolytic plating using an inexpensive printing method with excellent mass productivity, and it can shield near infrared rays and visible light without increasing special processes. Therefore, it is possible to produce a near infrared / electromagnetic wave shielding laminate excellent in light transmittance and electromagnetic wave shielding properties at low cost.

  The present invention will be described in detail with reference to the following examples and comparative examples.

Example 1
As a tungsten oxide-based near infrared absorber, a tungsten composite oxide (Cs _0.33 WO _x (where x = 2.2 to 2.99)) dispersion (solid content: 18.5) manufactured by Sumitomo Metal Mining Co., Ltd. Mass%) was used. Further, 60 g of alumina powder ((conductive paste-accepting oxide fine particles)) and 7 g of a phosphoric ester-based dispersant were placed in 333 g of toluene, and an alumina dispersion was prepared by a sand mill.
Dissolve 240 g of polyvinyl butyral in 1800 g of methyl ethyl ketone. To this solution, 1297 g of the tungsten composite oxide dispersion, 400 g of the alumina dispersion, 552 g of cyclohexanone, and 2111 g of toluene were added and mixed with a homogenizer to prepare a near-infrared shielding paint.
The obtained near-infrared shielding coating was applied to a 125 μm-thick PET film by microgravure printing, dried in air at a temperature of 120 ° C. for 2 minutes, and laminated on the PET film. A near infrared shielding PET film having a 2 μm near infrared shielding layer was obtained.

(Preparation of conductive paste and formation of mesh-like conductive paste printed film)
Silver powder (Dowa High-Tech, Ag-1S, average particle size: 0.9 μm, shape: granular) 67.0 parts by mass, and terpineol 28.5 parts by mass ethyl cellulose (Nisshin Kasei Co., EC (100 cP)) A resin solution in which 4.5 parts by mass were dissolved was blended and pre-kneaded, and then sufficiently pulverized and kneaded by a three-roll mill so that the maximum particle size by a particle gauge was 5 μm or less to obtain a conductive paste.

  Using the obtained conductive paste, a gravure printing plate of L / S = 20/280 μm is formed on the near-infrared shielding layer of the near-infrared shielding PET film at a speed of 10 m / min by the gravure printing method of FIG. Thus, a pattern of the conductive paste was printed in a mesh shape and dried at 120 ° C. for 3 minutes to obtain a printed mesh film on which the conductive pattern layer was formed.

(Electrolytic plating treatment)
The obtained printed mesh conductive paste layer-carrying PET film is immersed in an electrolytic copper plating solution (Okuno Pharmaceutical Co., Ltd., Top Lucina SF) at 25 ° C., phosphorous copper is used as the anode, and the above mesh conductive is used as the cathode. By using a paste layer carrying PET film and applying a direct current of 0.3 A / m ² for 10 minutes, an electrolytic copper plating film having a thickness of 2 μm was deposited on the conductive paste layer. Furthermore, a nickel / tin alloy plating with a film thickness of 0.3 μm is applied to blacken the mesh surface to form an electromagnetic wave shielding metal mesh layer shown in FIG. Obtained.

The near infrared / electromagnetic wave shielding laminate of Example 1 was evaluated. The evaluation results are shown in Table 1. Evaluation items and evaluation methods are as follows.
(1) Appearance observation: The near-infrared / electromagnetic wave shielding laminate was visually observed, and a mesh-like pattern with no disconnection, bleeding, or discoloration was evaluated as “no problem”. Discoloration ”was evaluated.
(2) Line width L / pitch S: Observed with an optical microscope, the line width L and the pitch S were measured at 10 locations, and the average line width L / pitch S was calculated.
(3) Sheet resistance: Measured according to the measurement method defined in JIS K-7194 “Resistivity test method of conductive plastics by 4-probe method”.
(4) Optical characteristics: Total light transmittance, transmittance at 850 nm and 950 nm, and transmission spectrum were measured using a spectrophotometer (UV / VIS / NIR Spectrometer V-570) manufactured by JASCO Corporation.
The transmission spectrum data of the laminate for shielding near infrared rays and electromagnetic waves of Example 1 is shown in FIG.

Example 2
In the same manner as in Example 1, a near infrared / electromagnetic wave shielding laminate was produced. However, IR-10A (manufactured by Nippon Shokubai), TX-EX-906B (manufactured by Nippon Shokubai), TX-EX-910B (manufactured by Nippon Shokubai) are used as phthalocyanine-based near infrared absorbers, and IR-10A 16. 8 g, 9 g of TX-EX-906B, and 15 g of TX-EX-910B were dissolved in 1200 g of methyl ethyl ketone to prepare a phthalocyanine solution. In addition, 60 g of alumina powder (oxide fine particles for receiving conductive paste) and 7 g of a phosphate ester dispersant were placed in 333 g of toluene, and an alumina dispersion was prepared by a sand mill.
Also, 240 g of polyvinyl butyral is dissolved in 1800 g of methyl ethyl ketone, and the phthalocyanine solution, the alumina dispersion, 552 g of cyclohexanone, and 1767.2 g of toluene are added to this solution and mixed uniformly to prepare a near infrared shielding coating. did.
Using this near infrared shielding paint, a near infrared shielding PET film was produced in the same manner as in Example 1.

Next, in the same manner as in Example 1, a near-infrared shielding PET film in which a conductive paste layer was laminated on the near-infrared shielding layer was produced. The shape of the obtained printing mesh was very good and there was no problem in appearance.
Further, in the same manner as in Example 1, the conductive paste mesh layer of the near-infrared shielding PET film was subjected to electrolytic copper plating and nickel / tin alloy plating to produce a near-infrared / electromagnetic wave shielding laminate. This near-infrared / electromagnetic wave shielding laminate was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1.

Example 3
A near-infrared / electromagnetic wave shielding laminate was produced and evaluated in the same manner as in Example 1. However, the line width L / pitch S of the gravure printing plate was changed to 10/290 μm. The evaluation results are shown in Table 1.

Example 4
A near infrared / electromagnetic wave shielding laminate was prepared and evaluated in the same manner as in Example 1. However, the alumina powder of the near-infrared shielding paint (oxide fine particles for accepting conductive paste) was changed to zirconia powder, the line width L / pitch S of the gravure plate was changed to 10/290 μm, and the printing speed Was changed to 20 m / min. The evaluation results are shown in Table 1.

Comparative Example 1
A near infrared / electromagnetic wave shielding laminate was produced and evaluated in the same manner as in Example 1. However, a diimonium dye CIR-1085 (manufactured by Nippon Carlit) was used as a near-infrared absorbing material, and 36 g of CIR-1085 was dissolved in 1200 g of methyl ethyl ketone to prepare a diimonium solution. Further, 60 g of alumina powder and 7 g of a phosphoric acid ester-based dispersant were placed in 333 g of toluene, and an alumina dispersion was prepared by a sand mill. Further, 240 g of polyvinyl butyral was dissolved in 1800 g of methyl ethyl ketone, and then the diimonium solution, the alumina dispersion, 552 g of cyclohexanone, and 1772 g of toluene were added and mixed to prepare a near-infrared shielding paint.
Using this near-infrared shielding coating, a near-infrared / electromagnetic wave shielding laminate was produced in the same manner as in Example 1. In this near-infrared / electromagnetic wave shielding laminate, the near-infrared shielding layer is discolored, resulting in appearance defects. The evaluation results are shown in Table 1.

  As can be seen from Table 1, the near-infrared / electromagnetic wave shielding laminates of Examples 1 to 4 according to the present invention have no deterioration of the near-infrared absorber as compared with that of the comparative example, and problems in appearance ( Discoloration) did not occur, and it was confirmed that the optical characteristics were excellent (transmittance at wavelengths 850 nm and 950 nm was low, that is, the shielding property in the near infrared region was good).

Cross-sectional explanatory drawing of an example of the laminated body for near infrared rays and electromagnetic wave shielding of this invention. Sectional explanatory drawing of the principal part of an example of the laminated body for near-infrared rays and electromagnetic wave shielding of this invention shown by FIG. Explanatory drawing which shows the structure of the gravure direct printing machine used for printing of an electrically conductive paste in an example of the manufacturing method of the laminated body for near-infrared rays and electromagnetic wave shielding of this invention. The top view which shows an example of the mesh pattern of the electromagnetic wave shielding layer of the laminated body for near infrared rays and electromagnetic wave shielding of this invention. The figure which shows the transmission spectrum of an example (Example 1) of the laminated body for near infrared rays and electromagnetic wave shielding of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Near-infrared ray / electromagnetic wave shielding laminate 2 Transparent substrate 3 Electromagnetic wave shielding metal mesh layer 4 Near infrared ray shielding layer 5 Functional layer 6 Adhesive layer 21 Conductive paste layer 22 Electrolytic plating layer 30 Gravure direct printing machine 31 First backup roll 32 Gravure plate 33 Doctor blade 34 Second backup roll 35 Transparent base material with near-infrared shielding layer 36 Conductive paste 37 Crimp part 38 Conductive paste layer

Claims (5)

A near-infrared ray comprising a transparent base, a near-infrared shielding layer formed on one main surface of the transparent base, and an electromagnetic shielding metal mesh layer formed on the near-infrared shielding layer. An electromagnetic wave shielding laminate,
The near-infrared shielding layer contains at least one selected from tungsten oxide-based and phthalocyanine-based near infrared absorbers, and a binder resin.
The electromagnetic wave shielding metal mesh layer is formed by applying electroplating to a mesh-like conductive pattern layer formed on the near infrared shielding layer. Laminated body.   On one main surface of the transparent substrate, at least one selected from tungsten oxide-based and phthalocyanine-based near-infrared absorbers, a binder resin, and a solvent for dissolving or dispersing the near-infrared absorber and the binder resin A step of forming a near infrared shielding layer by applying a near infrared shielding composition containing the composition and drying, and a conductive paste containing conductive particles is printed on the near infrared shielding layer in the form of a mesh An electromagnetic wave shielding metal mesh layer forming step including forming an electroconductive pattern layer and applying electroplating on the mesh conductive pattern layer to form an electromagnetic wave shielding metal mesh layer. A method for producing a laminate for shielding near infrared rays and electromagnetic waves.   The method for producing a near-infrared / electromagnetic wave shielding laminate according to claim 2, wherein, in the electromagnetic shielding metal mesh layer forming step, the conductive paste is printed using a gravure printing method.   Printing the conductive paste by the gravure printing method fills a groove formed in a mesh pattern on a gravure printing plate cylinder with the conductive paste, and a near-infrared shielding layer on the transparent substrate. Is applied by pressing the conductive paste on the plate cylinder directly onto the near-infrared absorbing layer without using a transfer sheet (blanket). 3. A method for producing a laminate for shielding near-infrared rays / electromagnetic waves according to item 3.   The method for producing a near-infrared / electromagnetic wave shielding laminate according to claim 4, wherein the predetermined pressure-bonding time in the transfer of the conductive paste is 0.5 seconds to 10 seconds.