JP2020026043A - Laminate - Google Patents

Abstract

To provide a laminate capable of preventing migration of a metal silver pattern under a high temperature and high humidity environment and improving the increase in a resistance value of the metal silver pattern due to sulfur components in the atmosphere.SOLUTION: A laminate is provided which comprises a metal silver pattern on a support and a protective layer containing a urethane resin having a structure derived from an aromatic isocyanate on the metal silver pattern.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a laminate that can be used for applications such as an electric circuit, an electromagnetic wave shielding material, and a touch panel.

  In electronic devices such as smartphones, personal digital assistants (PDAs), notebook PCs, tablet PCs, OA devices, medical devices, and car navigation systems, touch panel sensors are widely used as input means for these displays.

  Touch panel sensors include an optical method, an ultrasonic method, a resistive film method, a surface capacitive method, a projected capacitive method, etc., depending on the position detection method. The capacitance type is preferably used. The resistive touch panel sensor has a structure in which two conductive materials each having a light-transmitting conductive layer on a support are used and these conductive materials are arranged to face each other via a dot spacer. By applying a force to a point, the light-transmitting conductive layers come into contact with each other, and by measuring the voltage applied to each light-transmitting conductive layer through the other light-transmitting conductive layer, the position at the position where the force is applied is measured. It performs detection. On the other hand, a touch panel sensor of the projection capacitive type uses one conductive material having two light-transmitting conductive layers or two conductive materials having one light-transmitting conductive layer, and uses a finger or the like. The change in capacitance between the light-transmitting conductive layers when the finger is approached is detected, and the position where the finger is approached is detected. The latter has excellent durability because it has no movable parts, and is capable of performing simultaneous multipoint detection. Therefore, the latter is widely used particularly in smartphones and tablet PCs.

  In a projection-type capacitive touch panel sensor, a sensor unit consisting of multiple sensors obtained by patterning a light-transmitting conductive layer on a support is provided to allow simultaneous detection of multiple points and detection of moving points. Enables detection. In order to take out the change in capacitance detected by this sensor part as an electric signal to the outside, between all the sensors of the conductive material and the terminal part comprising a plurality of terminals provided to take out the electric signal to the outside Is provided with a peripheral wiring portion including a plurality of peripheral wirings for electrically connecting them. Usually, the light-transmitting conductive layer described above is located on the display, and the peripheral wiring portion and the terminal portion are located outside the display, that is, in a so-called frame portion. In the prior art, the light-transmitting conductive layer is generally formed of an ITO (indium-tin oxide) conductive film, and the peripheral wiring portions and terminal portions are formed of gold, silver, copper, nickel, aluminum, or the like. In general. For example, Japanese Patent Application Laid-Open No. 2015-32183 (Patent Document 1) discloses that a transparent conductor such as ITO, IZO (indium-zinc oxide), or ZnO (zinc oxide) is used as a material for a light-transmitting conductive layer, and the light-transmitting conductive layer is extracted. A touch panel sensor member using a metal such as copper as a material of a wiring (peripheral wiring portion) is disclosed.

  In recent years, there has been disclosed a conductive material having a mesh pattern of a mesh-like thin metal wire as a light-transmitting conductive layer, and a peripheral wiring portion formed of the same metal as the mesh pattern. For example, JP-A-2013-133239 (Patent Document 2) discloses a method in which a mesh pattern and a peripheral wiring portion are formed by printing an ink containing silver fine particles, or a resin paint containing an electroless plating catalyst. After that, a method of applying electroless plating, providing a photoresist layer on the metal layer, forming a resist pattern, and then removing the metal layer by etching, a method using a silver salt photosensitive material, etc., are formed by various methods. It states that it can.

  Among the metals forming the peripheral wiring and the mesh pattern, silver has the highest conductivity, so that a thin line having a smaller line width and a smaller film thickness can obtain higher conductivity than other metals. If the line width is small, the size of the electric circuit can be reduced, which is advantageous in terms of light transmittance and poor visibility of the pattern. Further, when the thickness of the fine wire is small, it becomes easy to provide various functional layers such as an adhesive layer and a hard coat layer on the pattern. For example, in an application such as an electromagnetic wave shielding film to be attached to a window glass or a touch sensor in which two electrodes are attached, when an adhesive layer is provided on the surface on the metallic silver pattern side, the thinner the metallic silver pattern, Since there is little mixing of air due to unevenness and it is easy to bond uniformly, it is a great advantage that the pattern is thin.

  Furthermore, when the pattern thickness is thin, the flexibility of wiring is greatly improved, so wiring and bonding to objects with curved surfaces are possible, and the application field is dramatically expanded from conventional flat devices to three-dimensional devices. In the future, expectations for conductive materials having a metallic silver pattern formed by fine lines containing silver are increasing.

  As a method of forming a metal silver pattern on a support, a subtractive method or a screen printing method as described above, and a method using a silver salt photosensitive material are known, and as a method using a silver salt photosensitive material, For example, a method using a silver salt diffusion transfer method as disclosed in WO 04/007810 pamphlet, a method using chemically developed silver as disclosed in JP-A-2004-221564, and the like are known. ing.

  Although the use of a metallic silver pattern as described above has many advantages, it has also been found that there are various problems. For example, silver easily undergoes ion migration, and when driven as an electronic circuit for a long time, the movement of silver ions may cause dielectric breakdown between electrodes. As a countermeasure, for example, JP-A-2009-188360 (Patent Document 3) and JP-A-2013-125797 (Patent Document 4) describe a method of adsorbing a mercapto-based compound on a metal wiring portion. Japanese Patent Application Laid-Open No. 2014-182436 (Patent Document 5) proposes a method in which a protective layer containing an epoxy resin is provided on a lead wiring containing metal silver and gelatin (synonymous with the above-described peripheral wiring).

  Furthermore, when these conductive materials are used outdoors such as for mobile applications, they are used in more severe environments than indoors. For example, in addition to higher temperature, higher humidity conditions, It is required to have good operation stability in an atmosphere where more corrosive sulfur components such as hydrogen sulfide and sulfurous acid gas contained in the gas are present. As a countermeasure, WO 2013/187324 (Patent Document 6) proposes a method of providing a sulfur-resistant resist layer made of a polyurethane-polyurea resin on a transparent electrode and a metal wiring. However, these methods are inadequate, and the recent trend toward finer metal silver patterns due to the higher definition of touch panels has made metal silver patterns more susceptible to the use environment. Demands for operational stability have become more severe.

JP-A-2005-32183 JP-A-2013-133239 JP 2009-188360 A JP 2013-125797 A JP 2014-182436 A WO 2013/187324 pamphlet

  An object of the present invention is to provide a laminate capable of preventing migration of a metallic silver pattern in a high-temperature and high-humidity environment and improving an increase in resistance of the metallic silver pattern due to a sulfur component in the atmosphere. .

The above object of the present invention is solved by the following invention.
A laminate having a metallic silver pattern on a support and a protective layer containing a urethane resin having a structure derived from an aromatic isocyanate on the metallic silver pattern.

  According to the present invention, it is possible to provide a laminate capable of preventing migration of a metallic silver pattern in a high-temperature and high-humidity environment and improving an increase in resistance of the metallic silver pattern due to a sulfur component in the atmosphere.

Schematic diagram of the transparent original pattern used in the embodiment Another schematic diagram of the transparent original pattern used in the embodiment

  As an example of the form of the laminate obtained by the present invention, a light-transmitting conductive material having a mesh-like metal silver pattern as a conductive metal portion on a support, or a metal in which peripheral wiring portions and terminal portions are drawn with silver A conductive material having a silver pattern can be used. Hereinafter, the present invention will be described in detail.

  The support of the laminate of the present invention may be either a support having light transmittance or a support having no light transmittance, but the laminate of the present invention is used for applications such as touch panel sensors. In this case, the support preferably has light transmittance from the viewpoint of transparency of the obtained laminate. Examples of the support having light transmittance include polyethylene, polyolefin resins such as polypropylene, polyvinyl chloride, vinyl chloride resins such as vinyl chloride copolymer, epoxy resin, polyarylate, polysulfone, polyether sulfone, polyimide, and the like. Various resin films such as fluororesin, phenoxy resin, triacetyl cellulose, polyethylene terephthalate, polyimide, polyphenylene sulfide, polyethylene naphthalate, polycarbonate, acrylic resin, cellophane, nylon, polystyrene resin, ABS resin, quartz glass, and alkali-free glass And the like. From the viewpoint of the transparency of the laminate, the total light transmittance of the support is preferably 60% or more, particularly preferably 70% or more. The support may have a known layer such as an easy-adhesion layer, a hard coat layer, an antireflection layer, an antiglare layer, and a conductive nonmetal layer made of ITO or the like.

  The method for forming the metallic silver pattern on the support is not particularly limited, and for example, a conductive metallic ink or conductive paste containing metallic silver and a binder is supported according to the method disclosed in JP-A-2015-67777. According to a method of forming a metallic silver pattern by applying a method such as printing on a body or a method disclosed in JP-A-2007-59270, a silver halide photosensitive material having a silver halide emulsion layer on a support is electrically conductive. A silver halide is formed on a support according to a method of forming a metallic silver pattern by using a hardening development method as a material precursor, a method disclosed in JP-A-2004-221564, JP-A-2007-12314, and the like. A method of using a silver salt photosensitive material having an emulsion layer as a conductive material precursor and forming a metallic silver pattern by a direct development method, JP-A-2003-77350 JP-A-2005-250169, JP-A-2007-188655, JP-A-2004-207001, and at least a physical development nucleus layer and a silver halide emulsion layer on a support. A method of forming a metallic silver pattern by using a so-called silver salt diffusion transfer method using a silver salt photosensitive material having this order as a conductive material precursor and allowing a soluble silver salt forming agent and a reducing agent to act in an alkaline solution, According to the method disclosed in JP-A-2004-197331, a base layer and a photosensitive resist layer are laminated on a support, and the photosensitive resist layer is exposed to an arbitrary pattern, developed, and formed into a resist image. Applying electroless plating to localize the metal on the underlying layer not covered with the resist image, and then removing the resist image to form a metallic silver pattern A metal film and a resist film are provided on a support in accordance with the method disclosed in Japanese Patent Application Laid-Open No. 2015-82178, and the resist film is exposed and developed to form an opening. To form a metallic silver pattern by etching away.

  Among the above-described methods for forming a metallic silver pattern, a method using a silver salt photosensitive material as a conductive material precursor is particularly preferable because the pattern can be easily formed and the pattern can be easily miniaturized.

  Among them, a method using a silver salt diffusion transfer method, which can easily and stably produce a uniform pattern having a fine wire thickness of preferably 1.0 μm or less, more preferably 0.3 μm or less, is particularly preferable. Further, most of the metallic silver pattern produced by the method using the silver salt diffusion transfer method is formed only of metallic silver, which is very preferable from the viewpoint of conductivity, and the thickness of the metallic silver pattern obtained is small. Even if it is thin, extremely high conductivity can be obtained. Further, in order to achieve high transmittance required for sensor electrodes for touch panels and the like, and excellent visibility of the silver pattern, a fine line width of 15 μm or less may be required, but a method using a silver salt diffusion transfer method is required. The obtained metallic silver is suitable because a uniform and high-definition image can be obtained.

  The silver salt diffusion transfer method, which is the most preferable method for forming a metallic silver pattern on the support in the laminate of the present invention, will be described in detail below.

  The conductive material precursor used in the silver salt diffusion transfer system has an undercoat layer containing at least a physical development nucleus on a support and a silver halide emulsion layer at least in this order from the side closer to the support. Further, the conductive material precursor may further have a non-photosensitive layer in the outermost layer farthest from the support, or may be provided between the undercoat layer containing physical development nuclei and the silver halide emulsion layer. May have an intermediate layer. After exposure to such a conductive material precursor in accordance with the required pattern, and then acted on in an alkaline developer containing a soluble silver complex forming agent and a reducing agent, a metallic silver pattern was formed on the undercoat layer. It is formed.

Examples of the physical development nuclei contained in the undercoat layer include fine particles (particle size of about 1 to several tens nm) of heavy metals or sulfides thereof. For example, colloids such as gold and silver; Metal sulfide obtained by mixing a neutral salt and a sulfide. The content of the physical development nuclei is suitably about 0.1 to 10 mg per 1 m ² in solid content.

  A silver halide emulsion layer is provided as an optical sensor on the undercoat layer or on the intermediate layer provided on the undercoat layer. Techniques used for silver halide, such as silver halide photographic films, photographic papers, printing plate making films, and photomask emulsion masks, can be used as they are.

  For forming silver halide emulsion grains used in the silver halide emulsion layer, Research Disclosure Item 17643 (December 1978) and 18716 (November 1979), 308119 such as forward mixing, reverse mixing, and simultaneous mixing are used. A publicly known method as described in (December 1989) can be used. Above all, it is preferable to use a so-called controlled double jet method, which is one of the simultaneous mixing methods and keeps pAg in a liquid phase in which grains are formed, constant, in that silver halide emulsion grains having a uniform grain size can be obtained. The average grain size of the preferred silver halide emulsion grains is 0.25 μm or less, particularly preferably 0.05 to 0.2 μm. The halogen composition of the silver halide emulsion has a preferable range, and preferably contains silver chloride in an amount of 80 mol% or more, and particularly preferably 90 mol% or more of silver chloride.

  In the production of a silver halide emulsion, a sulfite, a lead salt, a thallium salt, a rhodium salt or a complex salt thereof, an iridium salt or a complex salt thereof such as an iridium salt or a complex salt thereof may be formed, if necessary, in the process of forming silver halide grains or physical ripening. A salt of a metal element or a complex salt thereof may coexist. It can be sensitized by various chemical sensitizers, and methods commonly used in the art such as a sulfur sensitization method, a selenium sensitization method, and a noble metal sensitization method can be used alone or in combination. In the conductive material precursor used in the present invention, the silver halide emulsion can be dye-sensitized if necessary.

Further, the ratio of the amount of silver halide to the amount of gelatin contained in the silver halide emulsion layer is preferably such that the mass ratio of silver halide (in terms of silver) to gelatin (silver / gelatin) is 1.2 or more, More preferably, it is 1.5 or more. The amount of silver halide contained in the silver halide emulsion layer is preferably ² to 10 g / m ² in terms of silver.

  In the silver halide emulsion layer, known photographic additives can be used for various purposes. These are described in Research Disclosure Item 17643 (December 1978) and 18716 (November 1979), 308119 (December 1989), or in references cited.

  As described above, the non-photosensitive layer of the conductive material precursor may be provided between the silver halide emulsion layer and the undercoat layer containing physical development nuclei or on the silver halide emulsion layer. These non-photosensitive layers are layers containing a water-soluble polymer compound as a main binder. The water-soluble polymer compound as used herein may be any compound as long as it easily swells with the developer and easily penetrates the developer into the underlying silver halide emulsion layer and the physical development nucleus layer.

  Specifically, gelatin, albumin, casein, polyvinyl alcohol and the like can be used. Particularly preferred water-soluble polymer compounds are proteins such as gelatin, albumin, and casein. In order to sufficiently obtain the effects of the present invention, the amount of the binder in the non-photosensitive layer is preferably in the range of 20 to 100% by mass, more preferably 30 to 80% by mass, based on the total amount of the binder in the silver halide emulsion layer. % Is preferred.

  These non-photosensitive layers may be added, if necessary, to known photographic additives as described in Research Disclosure Item 17643 (December 1978) and 18716 (November 1979) and 308119 (December 1989). An agent can be contained. Further, as long as the peeling of the silver halide emulsion layer after the processing is not hindered, the film can be hardened with a crosslinking agent.

As the conductive material precursor, a non-sensitizing dye or pigment having an absorption maximum in the photosensitive wavelength region of the silver halide emulsion layer is preferably used as a halation or irradiation inhibitor for improving image quality. As the antihalation agent, an undercoating layer preferably containing the above-described physical development nucleus, or an intermediate layer optionally provided between the undercoating layer and the silver halide emulsion layer, or provided with a support interposed therebetween Can be contained in the backing layer. The irradiation inhibitor is preferably contained in a silver halide emulsion layer. The amount of addition may vary over a wide range as long as the desired effect is obtained. For example, when it is contained in the backing layer as an antihalation agent, the amount is preferably in the range of about 20 mg to about 1 g per 1 m ² , and more preferably, The absorbance at the maximum absorption wavelength is 0.5 or more.

  Exposure for drawing a metallic silver pattern on the conductive material precursor will be described. The silver halide emulsion layer of the conductive material precursor is exposed imagewise. As an exposure method, a method in which a transparent original having a desired pattern is brought into close contact with the surface having the silver halide emulsion layer, or various types of exposure are used. There is a method of scanning and exposing a desired pattern using a laser beam. In the above-described method of exposing with laser light, for example, a blue semiconductor laser (also referred to as a violet laser diode) having an oscillation wavelength of 400 to 430 nm can be used.

  The development process of the exposed conductive material precursor will be described. The silver halide emulsion layer of the conductive material precursor that has been imagewise exposed as described above is treated in an alkali developer (silver salt diffusion transfer developer) containing a soluble silver complex-forming agent and an alkali agent. Physical development occurs, and the silver halide that does not have a latent image nucleus enough to be developed is dissolved by a soluble silver complex forming agent to form a silver complex, and is reduced on the physical development nucleus in the undercoat layer to form metallic silver. It is possible to obtain a silver thin film having a mesh pattern by precipitation. On the other hand, silver halide having a latent image nucleus that can be developed by exposure is chemically developed in a silver halide emulsion layer to become blackened silver. After the development, the unnecessary silver halide emulsion layer (including blackened silver), the intermediate layer, the protective layer and the like are removed, and the silver thin film is exposed on the surface.

  As a method for removing the silver halide emulsion layer or the like after the development processing, there is a method of washing and removing or transferring and peeling to a release paper or the like. Washing and removing includes a method of removing the hot water while spraying it with a scrubbing roller or the like, and a method of removing the water by jetting hot water with a nozzle or the like and using the force of water. Further, in the method of transferring and peeling with a release paper or the like, the excess alkali developing solution on the silver halide emulsion layer is squeezed in advance with a roller or the like, and the silver halide emulsion layer or the like is brought into close contact with the release paper to make the silver halide emulsion layer. And the like are transferred from a plastic resin film to a release paper and peeled off. As the release paper, water-absorbing paper or nonwoven fabric, or a paper having a water-absorbing void layer formed of a fine particle pigment such as silica and a binder such as polyvinyl alcohol on paper is used.

  The soluble silver complex forming agent contained in the silver salt diffusion transfer developer is a compound that dissolves silver halide to form a soluble silver complex, and the reducing agent reduces the soluble silver complex to form a metal on the physical development nucleus. It is a compound for depositing silver.

  Soluble silver complex forming agents contained in the silver salt diffusion transfer developer include thiosulfates such as sodium thiosulfate and ammonium thiosulfate, thiocyanates such as sodium thiocyanate and ammonium thiocyanate, sodium sulfite and potassium bisulfite. Sulfoxides, oxazolidones, 2-mercaptobenzoic acid and derivatives thereof, cyclic imides such as uracil, alkanolamines, diamines, mesoionic compounds described in JP-A-9-171257, U.S. Pat. No. 200,294, thioethers, 5,5-dialkylhydantoins, alkylsulfones, and others, "The Theory of the Photographic Process (4th edition, p. 474-475)", T.A. H. Compounds described by James. These soluble silver complexing agents can be used alone or in combination.

  The reducing agent contained in the silver salt diffusion transfer developer is in the field of photographic development as described in Research Disclosure Item 17643 (December 1978) and 18716 (November 1979) and 308119 (December 1989). And a known developing agent can be used. For example, polyhydroxybenzenes such as hydroquinone, catechol, pyrogallol, methylhydroquinone, chlorohydroquinone, ascorbic acid and derivatives thereof, 1-phenyl-4,4-dimethyl-3-pyrazolidone, 1-phenyl-3-pyrazolidone, 1-phenyl Examples thereof include 3-pyrazolidones such as phenyl-4-methyl-4-hydroxymethyl-3-pyrazolidone, paramethylaminophenol, paraaminophenol, parahydroxyphenylglycine, and paraphenylenediamine. These reducing agents can be used alone or in combination.

  The content of the soluble silver complex-forming agent is preferably from 0.001 to 5 mol, more preferably from 0.005 to 1 mol, per liter of the silver salt diffusion transfer developer. The content of the reducing agent is preferably from 0.01 to 1 mol, more preferably from 0.05 to 1 mol, per liter of the developer.

  The pH of the silver salt diffusion transfer developer is preferably 10 or more, more preferably 11 to 14. In order to adjust to a desired pH, an alkali agent such as sodium hydroxide and potassium hydroxide, and a buffering agent such as phosphoric acid and carbonic acid are contained alone or in combination. The silver salt diffusion transfer developer preferably contains a preservative such as sodium sulfite or potassium sulfite.

  The application of the developer for diffusion transfer development of the conductive material precursor described above may be a method of dipping or applying the developer. The immersion method is, for example, a method in which the exposed conductive material precursor is conveyed while being immersed in a developer stored in a large amount in a tank, and the coating method is, for example, the developer is applied to the silver halide emulsion layer side. About 40 to 120 ml is applied per square meter. As a specific method of the immersion method, for example, a processing method and a processing apparatus disclosed in JP-A-2006-190535 can be exemplified. The method described in this publication is preferably based on non-contact transport of the surface of the conductive material on which the metallic silver pattern is provided, so that disconnection of the metallic silver pattern hardly occurs. The application temperature of the developer is preferably from 2 to 30C, more preferably from 10 to 25C. The application time of the developer is suitably about 20 seconds to 3 minutes. This embodiment is particularly suitable for the immersion method.

  In the present invention, the metallic silver pattern formed on the support is preferably a mesh pattern. In the present invention, the mesh pattern means a pattern having a geometrical shape in which a plurality of unit cells are arranged in a mesh pattern. Examples of the shape of the unit cell include equilateral triangles, isosceles triangles, triangles such as right triangles, and the like. Squares such as squares, rectangles, rhombs, parallelograms, trapezoids, etc., hexagons, octagons, dodecagons, n-sides such as decagons, and shapes combining stars, etc., and these shapes alone Or a combination of two or more types of plural shapes. Above all, a square or rhombus is preferable as the shape of the unit lattice, and an irregular geometric shape represented by a Voronoi figure, a Delaunay figure, a pentile figure, etc. is also one of the preferable mesh patterns in the present invention. The line width of the fine lines constituting these mesh patterns is preferably 20 μm or less, more preferably 1 to 15 μm.

  When the metallic silver pattern formed on the support is a peripheral wiring, the line width of the metallic silver pattern on the support is not particularly limited, but may be 10 to 1000 μm from the viewpoint of ensuring the conductivity of the peripheral wiring. It is more preferably 15 to 750 μm, and particularly preferably 20 to 500 μm. The distance between the peripheral wirings is not particularly limited, but is preferably 10 to 1000 μm, more preferably 15 to 750 μm, and particularly preferably 20 to 500 μm from the viewpoint of narrowing the frame by miniaturizing the peripheral wirings.

  In the present invention, the metallic silver pattern formed on the support may be a comb-shaped electrode. In this case, each of the comb-shaped electrodes alternates between the electrode portions (comb-shaped portions) of the respective comb-shaped electrodes. It is preferable that the comb-shaped electrode has a fine line of 20 to 500 μm at an interval of 20 to 500 μm, especially when the electrode portions are arranged at positions facing each other alternately. It is particularly preferred that the spacing between the electrodes be equal.

  Next, the protective layer provided on the metallic silver pattern in the present invention will be described.

  In the present invention, the protective layer contains a urethane resin having a structure derived from an aromatic isocyanate. Such a urethane resin can be obtained by synthesizing a polyol such as a polycarbonate polyol, a polyester polyol, or a polyether polyol, and a polyisocyanate compound having an aromatic ring.

  Polycarbonate polyols are obtained from a polyhydric alcohol and a carbonate compound by a dealcoholization reaction. Polyhydric alcohols include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentane Diol, 1,6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decane Diol, neopentyl glycol, 3-methyl-1,5-pentanediol, 3,3-dimethylolheptane and the like. Examples of the carbonate compound include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, and ethylene carbonate. Polycarbonate polyols obtained from these reactions include, for example, poly (1,6-hexylene) carbonate, poly (3-methyl) (-1,5-pentylene) carbonate and the like.

  Polyester polyols include polycarboxylic acids (malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, sebacic acid, fumaric acid, maleic acid, terephthalic acid, isophthalic acid, etc.) or anhydrides thereof. And polyhydric alcohols (ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2-methyl-2,4-pentanediol , 2-methyl-2-propyl-1 3-propanediol, 1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2,5-dimethyl-2,5-hexanediol , 1,9-nonanediol, 2-methyl-1,8-octanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-butyl-2-hexyl-1,3-propanediol, cyclohexane Diol, bis (hydroxymethyl) cyclohexane, dimethanolbenzene, bis (hydroxyethoxy) benzene, alkyl dialkanolamine, lactone diol, etc.).

  Examples of the polyether polyols include polyethylene glycol, polypropylene glycol, polyethylene propylene glycol, polytetramethylene ether glycol, polyhexamethylene ether glycol, and the like.

  Examples of the polyisocyanate compound having an aromatic ring include tolylene diisocyanate, xylylene diisocyanate, methylene diphenyl diisocyanate, phenylene diisocyanate, naphthalene diisocyanate, and tolidine diisocyanate.

  In the present invention, a silver salt diffusion transfer method is most preferably used for forming a metallic silver pattern on a support, but a urethane resin having a structure derived from an aromatic isocyanate (hereinafter referred to as an aromatic isocyanate-based urethane resin). ) Is provided as a protective layer, from the viewpoint of adhesion to a support (particularly a support provided with a physical development nucleus layer), an aqueous or emulsion type aromatic isocyanate-based urethane resin using water as a medium is preferable. It is.

  As a method for obtaining such an aqueous aromatic isocyanate-based urethane resin, for example, the above-mentioned polyol and the above-mentioned polyisocyanate compound having an aromatic ring are reacted to form an isocyanate group-terminated urethane prepolymer, and ammonia or A method of neutralizing an anionic group with a tertiary amine (such as triethylamine) and dispersing the same in water, and performing a chain extension reaction with water and a polyamine; A method of reacting with an isocyanate compound to form a hydroxyl group-terminated urethane prepolymer, neutralizing an anionic group with ammonia or a tertiary amine (such as triethylamine) if necessary, and dispersing the anionic group in water, may be mentioned.

  In addition, the aromatic isocyanate-based urethane resin in the present invention preferably has a dispersed particle diameter of 0.01 to 0.1 μm from the viewpoint of the transparency of the obtained protective layer, and as such an aromatic isocyanate-based urethane resin. Is commercially available from Daiichi Kogyo Seiyaku Co., Ltd. as Superflex (registered trademark) 830HS, Superflex 870, or the like, which is an aromatic isocyanate-based urethane resin and has a different dispersed particle size. It is possible.

Solid content of the protective layer in the present invention is preferably at 0.05 g / ^{m 2} or more, more preferably 0.5 g / ^{m 2} or more. If the solid content of the protective layer is less than this, if current is applied under conditions of high temperature and high humidity, dielectric breakdown between the electrodes may occur, and a sufficient migration prevention effect may not be obtained, and sufficient corrosion resistance may not be obtained. May not be obtained. On the other hand, if the solid content of the protective layer is too large, the high flexibility of the metallic silver pattern may be adversely affected. Furthermore, when an electric signal is extracted from the laminate of the present invention, a wiring pattern for extraction is pressed on the protective layer via an ACF (anisotropic conductive film), and is generally included in the anisotropic conductive film. Since the diameter of the conductive particles to be formed is 10 to 20 μm, if the solid content of the protective layer is too large, the conductive particles cannot contact the surface of the metallic silver pattern, and it may be difficult to take out an electric signal. Therefore, the solid content of the protective layer of the present invention is preferably 20 g / m ² or less.

  In the present invention, the protective layer may contain a crosslinking component in addition to the above-mentioned aromatic isocyanate-based urethane resin, and examples thereof include existing crosslinking agents such as carbodiimide-based, isocyanate-based, aziridine-based, epoxy-based, and oxazoline-based crosslinking agents.

  Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist.

<Example 1>
A polyethylene terephthalate film having a thickness of 100 μm was used as a support. The total light transmittance of the support was 91%.

  Next, a physical development nucleus layer having the following composition was coated on a support and dried to provide a physical development nucleus layer.

<Preparation of palladium sulfide sol>
Solution A 5g palladium chloride
Hydrochloric acid 40ml
Distilled water 1000ml
Liquid B 8.6g Sodium sulfide
Distilled water 1000ml
Solution A and solution B were mixed with stirring, and after 30 minutes, passed through a column filled with an ion exchange resin to obtain a palladium sulfide sol.

<Physical development nucleus layer composition / per 1 m ² >
0.4 mg of the above palladium sulfide sol (as solid content)
2mg% glyoxal aqueous solution 200mg
Surfactant (S-1) 4mg
Denacol (registered trademark) EX-830 25 mg
(Polyethylene glycol diglycidyl ether manufactured by Nagase ChemteX Corporation)
500 mg of 10% by mass Epomin (registered trademark) HM-2000 aqueous solution
(Polyethyleneimine manufactured by Nippon Shokubai Co., Ltd .; average molecular weight 30,000)

  Subsequently, an intermediate layer, a silver halide emulsion layer, and an overlayer having the following compositions were coated on the physical development nucleus liquid layer in the order from the side closest to the support and dried to obtain a silver salt photosensitive material. The silver halide emulsion was produced by a general double jet mixing method of a photographic silver halide emulsion. This silver halide emulsion was prepared so that the average grain size was 95 mol% of silver chloride and 5 mol% of silver bromide and 0.15 μm. The silver halide emulsion thus obtained was subjected to gold sulfur sensitization using sodium thiosulfate and chloroauric acid according to a conventional method. The silver halide emulsion thus obtained contains 0.5 g of gelatin per gram of silver.

<Intermediate layer composition / 1 m ² per>
0.5g gelatin
Surfactant (S-1) 5mg
Dye 15mg

<Silver halide emulsion layer composition / per 1 m ² >
0.5g gelatin
Silver halide emulsion 3.0 g Silver equivalent 1-phenyl-5-mercaptotetrazole 3 mg
Surfactant (S-1) 20mg

<Over layer composition / 1m ² per>
1g gelatin
Amorphous silica matting agent (average particle size 3.5 μm) 10 mg
Surfactant (S-1) 10mg

  The conductive material precursor thus obtained was exposed to a transparent original having the pattern shown in FIG. 1 in close contact with a contact printer using a mercury lamp as a light source. In the pattern of FIG. 1, the mesh pattern portion a is made of a mesh in which a square having a fine line width of 10 μm and a fine line interval of 300 μm is a unit figure, and b is a peripheral wiring portion in which peripheral line portions having a line width of 40 μm are arranged at intervals of 30 μm. , C are non-image parts (non-conductive parts).

  Similarly, the conductive material precursor was exposed to a transparent original having the pattern shown in FIG. 2 in close contact with a contact printer using a mercury lamp as a light source. In the pattern of FIG. 2, d is an anode-side comb-shaped electrode and f is a cathode-side comb-shaped electrode, and d and f have a comb-tooth-shaped line width of 50 μm and a line interval of 150 μm, respectively. . These comb-shaped electrodes are arranged so as to face each other alternately and have no electrical continuity. In the pattern of FIG. 2, e is an anode-side comb electrode terminal, and g is a cathode-side comb electrode terminal. Further, a portion h surrounded by a dotted line in FIG. 2 is a portion where OCA (transparent optical adhesive film) is bonded. The exposure amount in the patterns of FIGS. 1 and 2 was such that the fine line width of the metallic silver pattern forming the conductive portion was the same as the fine line width of each transparent original.

  Thereafter, the exposed conductive material precursor was immersed in a silver salt diffusion transfer developer having the following composition at 20 ° C. for 60 seconds, and then the silver halide emulsion layer, intermediate layer, and protective layer were washed off with warm water at 40 ° C. Then, a drying process was performed to obtain a conductive material A having the pattern shape of FIG. 1 and a conductive material B having the pattern shape of FIG. When the fine line widths and pitches of the obtained conductive materials A and B were confirmed with an optical microscope, the fine line widths and pitches of the transparent originals in FIGS. 1 and 2 were reproduced, respectively. When the film thickness of the thin line portion was examined with a confocal microscope (Opterix (registered trademark) C130, manufactured by Lasertec), it was 0.15 μm.

<Silver salt diffusion transfer developer composition>
25 g of potassium hydroxide
Hydroquinone 18g
1-phenyl-3-pyrazolidone 2g
80 g of potassium sulfite
N-methylethanolamine 15g
1.2 g of potassium bromide
The total volume was adjusted to 1000 ml with water and the pH was adjusted to 12.2.

  A protective layer having the following composition is applied on the metallic silver pattern of the pattern of FIGS. 1 and 2 obtained as described above with a film applicator, and dried with a hot air at 80 ° C. for 2 minutes using a film dryer. Thus, a laminate of Example 1 was produced.

<Protective layer composition (1) / per 1 m ² >
Aromatic isocyanate-based urethane resin 1 (as solid content) 0.05 g
(Superflex 830HS manufactured by Daiichi Kogyo Seiyaku Co., Ltd., dispersed particle size 0.01 μm)

<Examples 2 to 4>
The solid content of the aromatic isocyanate-based urethane resin in Example 1, respectively ^{0.5g / m 2, 1.0g / m} 2, except that was changed to 10.0 g / ^{m 2} in the same manner as in Example 1 Example 2 to 4 laminates were produced.

<Example 5>
A laminate of Example 5 was produced in the same manner except that the composition of the protective layer (1) in Example 1 was changed to the composition of the protective layer (2) having the following composition.

<Protective layer composition (2) / per 1 m ² >
Aromatic isocyanate urethane resin 2 (as solid content) 0.05 g
(Daiichi Kogyo Seiyaku Co., Ltd. Superflex 870 dispersed particle size 0.03 μm)

<Examples 6 to 8>
The solid content of the aromatic isocyanate-based urethane resin 2 of Example 5, respectively ^{0.5g / m 2, 1.0g / m} 2, in the same manner as in Example 5 except that the 10.0 g / ^{m 2} embodiment The laminates of Examples 6 to 8 were produced.

<Comparative Example 1>
The laminate of Comparative Example 1 was provided without providing a protective layer on the pattern.

<Comparative Example 2>
A laminate of Comparative Example 2 was produced in the same manner as in the production of the laminate of Example 1, except that the protective layer composition (1) was changed to the protective layer composition (3) having the following composition.

<Protective layer composition (3) / per 1 m ² >
Aliphatic isocyanate urethane resin 1 (as solid content) 1.0 g
(Daiichi Kogyo Seiyaku Co., Ltd., Superflex 420, dispersed particle size 0.01 μm)

<Comparative Example 3>
A laminate of Comparative Example 3 was produced in the same manner as in the production of the laminate of Example 1, except that the protective layer composition (1) was changed to the following protective layer composition (4).

<Protective layer composition (4) / per 1 m ² >
Aliphatic isocyanate urethane resin 2 (as solid content) 1.0 g
(Daiichi Kogyo Seiyaku Co., Ltd. Superflex 150 dispersed particle size 0.03 μm)

<Comparative Example 4>
A laminate of Comparative Example 4 was produced in the same manner as in the production of the laminate of Example 1, except that the protective layer composition (1) was changed to the following protective layer composition (5).

<Protective layer composition (5) / per 1 m ² >
1.0 g of polyvinyl alcohol
(Saponification degree 88%, average polymerization degree 1700)

<Comparative Example 5>
A laminate of Comparative Example 5 was produced in the same manner as in the production of the laminate of Example 1, except that the protective layer composition (1) was changed to the protective layer composition (6) having the following composition.

<Protective layer composition (6) / per 1 m ² >
1.0 g of sodium polyacrylate
(Average degree of polymerization 5000)

  The electric resistance value A between the tips of the two outermost peripheral wiring portions b of the laminate having the same pattern shape as the pattern of FIG. 1 obtained as described above was measured using a tester.

  Next, after sealing the tip of the peripheral wiring portion b in FIG. 1 (the lower central portion in the drawing) with a masking tape, put it in a gas corrosion tester KG200 manufactured by Factkei Co., Ltd., and expose it to hydrogen sulfide for 24 hours. The test was performed. The gas concentration of hydrogen sulfide used in the exposure test was 5 ppm, the temperature was 35 ° C., and the relative humidity was 95%. After the test, the masking tape was peeled off, and the electric resistance B between the tips of the two outermost peripheral wiring portions b was measured with a tester in the same manner as before the exposure test.

<Evaluation of resistance rise>
The rate of increase in resistance between electrode terminals before and after exposure to hydrogen sulfide ({(B−A) / A} × 100) was evaluated according to the following criteria.

Resistance rise rate evaluation standard “○”: Resistance rise rate before and after exposure is less than 5%.
“Δ”: The rate of increase in resistance before and after exposure is 5% or more and less than 50%.
“×”: The rate of increase in resistance before and after exposure was 50% or more.

  OCA8146-4 manufactured by 3M Co., Ltd. was bonded to the portion (h in FIG. 2) of the laminate having the same pattern shape as the pattern of FIG. 2 obtained as described above and overlapping. Next, with the anode-side terminal of the DC power supply connected to the anode-side comb-shaped electrode terminal portion e and the cathode-side terminal connected to the cathode-side comb-shaped electrode terminal portion g, the inside of a constant temperature and humidity machine PR-2KT manufactured by Espec Corporation is used. And a DC voltage of 20 V was continuously applied for 18 hours in an environment of a temperature of 60 ° C. and a relative humidity of 90%.

<Migration resistance evaluation>
The insulating state between the anode-side comb electrode d and the cathode-side comb electrode f was evaluated based on the following criteria, and is shown in Table 1.

Insulation state evaluation standard "O": No conduction is observed between the electrodes.
“×”: Conduction occurred between the electrodes.

  From the results shown in Table 1, the present invention provides a laminate capable of preventing migration of a metallic silver pattern in a high-temperature and high-humidity environment and improving a rise in resistance of the metallic silver pattern due to a sulfur component in the atmosphere. be able to.

a Mesh pattern portion b Peripheral wiring portion c Non-image portion d Anode-side comb electrode e Anode-side comb electrode terminal f Cathode-side comb electrode g Cathode-side comb electrode terminal h OCA bonding portion

Claims (1)

  A laminate having a metallic silver pattern on a support and a protective layer containing a urethane resin having a structure derived from an aromatic isocyanate on the metallic silver pattern.

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