JP4624896B2 - Conductive material precursor - Google Patents

Description

  The present invention relates to a conductive material that can be used for applications such as an electronic circuit, an antenna circuit, an electromagnetic wave shielding material, and a touch panel, and more particularly to a method for producing a transparent conductive material having a metal part and a light transmission part.

  In recent years, with the rapid development of the information-oriented society, technologies related to information-related devices have rapidly advanced and become popular. Among them, the display device is used for televisions, personal computers, guidance displays for stations, airports, and other information. In particular, plasma displays have attracted attention in recent years.

  In such an information society, there is a concern about the influence of electromagnetic waves radiated from these display devices. For example, the influence on surrounding electronic devices and the influence on the human body are considered. In particular, the impact on human health is not negligible, and there is a need to reduce the strength of the electromagnetic field applied to the human body, and various transparent conductive materials have been developed to meet these requirements. Has been. For example, JP-A-9-53030, JP-A-11-122024, JP-A-2000-294980, JP-A-2000-357414, JP-A-2000-329934, JP-A-2001-38843, JP-A-2001-47549. JP-A-2001-51610, JP-A-2001-57110, JP-A-2001-60416, and the like.

  As a method for producing these transparent conductive materials, a conductive metal such as silver, copper, nickel, or indium is formed on a transparent resin film by sputtering, ion plating, ion beam assist, vacuum deposition, or wet coating. In general, a method of forming a metal thin film is generally used. However, since these conventional methods are extremely complicated, there has been a problem of high cost and poor productivity.

  Another performance required for the transparent conductive material is conductivity and light transmittance. In order to increase the conductivity, it is necessary to make a metal thin film fine pattern with a certain width and thickness, but at the same time, increasing the line width of the metal pattern that blocks light reduces the transmittance. In order to satisfy the above, it is necessary to manufacture a fine metal pattern having sufficient conductivity, particularly a uniform pattern with a minimum necessary width, but this cannot be satisfied by the conventional method.

  In view of producing a uniform pattern, a method of using a silver salt photographic light-sensitive material containing a silver halide emulsion layer as a transparent conductive material precursor has been proposed in recent years. For example, International Publication No. WO01 / 51276 (Patent Document 1) proposes a method for producing a transparent conductive material by subjecting a silver salt photographic light-sensitive material to image exposure and development, and then performing metal plating. . That is, there is a problem that another process called plating is inevitably used without obtaining electrical conductivity by image exposure and development fixing alone, which are ordinary photographic processing. Moreover, developed silver is used as a catalyst for plating, but the developed silver is buried in gelatin as a binder, and it is difficult to contact with the plating solution and it is difficult to plate. ing. In Japanese Patent Application Laid-Open No. 2004-221564 (Patent Document 2), the efficiency is increased by increasing the silver ratio by changing the silver / gelatin ratio in the silver halide emulsion layer in order to increase the plating efficiency. I am trying to do. However, the plating process is indispensable also in this invention, and when trying to make such a silver halide emulsion, only a very small amount of protective binder can be used, and it is possible to hold silver with a high specific gravity with such a small amount of binder. There were problems in production such as difficulty and the tendency to fog due to pressure applied during production.

  Similarly, a method using a silver salt diffusion transfer method has been proposed as a method of using a silver salt photosensitive material, for example, International Publication No. WO2004-007810 (Patent Document 3). In this method, silver is not covered with a very small amount of binder or substantially covered with a binder, so that a certain degree of conductivity can be obtained without plating. Further, since there is no binder, the plating solution and the developed silver are easily contacted, and this is an advantageous technique for plating. However, since a thick and heavy silver halide emulsion layer is coated on a very thin physical development nucleus layer, simultaneous multi-layer coating is difficult and there is a problem that productivity is deteriorated.

In JP-A-2005-15068 (Patent Document 4), an ultraviolet curable resin containing an electroless plating catalyst and an alkali-soluble resin is printed on a transparent substrate to form a pattern, and the resin is cured by irradiating ultraviolet rays. A method of electroless plating to make a conductive material has been proposed. According to this method, since the alkali-soluble resin is dissolved in the alkaline electroless plating solution, the plating catalyst buried in the resin appears on the surface, and the plating becomes easy. In this method, since an ultraviolet resin having almost no water swellability is used, the conductive metal film is formed on the resin pattern as described in FIG. The present invention is basically different from the present application in that it relates to a metal formed in an iso-water-swellable binder and that this method absolutely requires electroless plating. In this method, since the alkali-soluble resin is successively dissolved in the thermodynamically unstable plating solution, there is a drawback that fatigue of the plating solution is extremely accelerated.
International Patent Publication No. WO01 / 51276 (1 page) JP 2004-221564 A (pages 1 to 5) International Patent Publication No. WO2004 / 221565 (1 page) Japanese Patent Laying-Open No. 2005-15068 (1 page, FIG. E)

  Accordingly, an object of the present invention is to provide a production method for obtaining a conductive material having both high transparency and conductivity and high productivity.

The above object of the present invention is to provide a conductive material precursor containing at least one silver halide emulsion layer on a support, the conductive material precursor having no physical development nucleus layer, and the silver halide. This was achieved by using a conductive material precursor characterized in that the sol fraction of the total hydrophilic binder in the emulsion layer was 10% by mass or more.

  According to the method for producing a transparent conductive material of the present invention, it was possible to provide a production method for obtaining a conductive material having both high transparency and high conductivity and good productivity.

  The inventors of the present invention use a known silver salt photographic light-sensitive material, which is formed by a normal development process when producing a silver salt photographic light-sensitive material having a silver halide emulsion layer as a precursor of a conductive material. As a result of intensive studies to improve the disadvantage that conductivity cannot be obtained because the developed silver is isolated from each other by the binder, a part of the binder is removed at the stage of the development process, and the developed silver is brought into contact with each other. As a result, it was found that this problem can be solved, and the present invention has been achieved. Further, the present inventors have found that the unexposed portion is not particularly affected by the method of the present invention, and at the same time, high transparency which is a characteristic of a conductive material using a silver salt photographic light-sensitive material as a conductive precursor can be obtained. Furthermore, since the efficiency of electroless plating can be increased in this method, higher conductivity can be obtained.

  Examples of the transparent support used for the conductive material precursor of the present invention include polyester resins such as polyethylene terephthalate, diacetate resins, triacetate resins, acrylic resins, polycarbonate resins, polyvinyl chloride, polyimide resins, cellophane, and celluloid. Examples thereof include a plastic resin film and a glass plate. Furthermore, in the present invention, an undercoat layer or an antistatic layer for improving the adhesion to the silver halide photographic emulsion layer can be provided on the support, if necessary.

  In the conductive material precursor of the present invention, a photosensitive silver halide emulsion layer is provided on a support as an optical sensor. Techniques used in silver halide photographic films, photographic papers, printing plate-making films, emulsion masks for photomasks, etc. relating to silver halide can also be used as they are in the present invention.

  The average grain size of the preferred silver halide emulsion grains of the photosensitive silver halide crystals is 0.25 μm or less, particularly preferably 0.05 to 0.2 μm. The shape of the silver halide grains in the present invention is not particularly limited. For example, various shapes such as a spherical shape, a cubic shape, a flat plate shape (hexagonal flat plate shape, triangular flat plate shape, tetragonal flat plate shape, etc.), octahedral shape, and tetradecahedral shape are available. It can be a simple shape.

  The halogen element contained in the photosensitive silver halide grain in the present invention may be any of chlorine, bromine, iodine and fluorine, and may be a combination thereof, but it is particularly preferred to contain chlorine. For the formation of silver halide emulsion grains, methods well known in the art such as forward mixing, reverse mixing, and simultaneous mixing are used. Among them, it is preferable to use a so-called controlled double jet method, which is one of the simultaneous mixing methods and keeps the pAg in the liquid phase to be formed constant, from the viewpoint of obtaining silver halide emulsion grains having a uniform particle size. . In the present invention, the average grain size of preferable silver halide emulsion grains is 0.25 μm or less, particularly preferably 0.05 to 0.2 μm.

  The shape of the photosensitive silver halide grain in the present invention is not particularly limited. For example, the shape is spherical, cubic, tabular (hexagonal flat, triangular flat, quadrangular flat, etc.), octahedral, and tetrahedral. It can be various shapes.

Photosensitive silver halide grains in the present invention 0.15~5g / m ² in terms of silver in the silver halide emulsion layer, preferably 0.3 to 1 g / m ² is contained.

The sol fraction of the total hydrophilic binder in the silver halide emulsion layer in the conductive material precursor of the present invention means the proportion of the water-eluting binder component in the hydrophilic binder constituting the silver halide emulsion layer. In the present invention, the sol fraction is prepared by coating only a silver halide emulsion layer on a transparent support with the same coating amount as that of the conductive material precursor, and preparing a sample for sol fraction measurement by drying under the same drying conditions. After immersing in warm water at 1 ° C. for 1 hour and drying, it is determined by measuring the weight change before and after that. In the case of a conductive material precursor having no overlayer or undercoat layer, it can be used as a sample for sol fraction by removing the backcoat layer. At least 0.05 m ² or more in the sol fraction measurements to reduce the measurement errors, but it is preferable to use a 0.1 m ² or more samples. The support used as the sample for sol fraction measurement may be a support having no water permeability, and the same transparent support used as the support for the conductive material precursor of the present invention is preferably used.

  In the present invention, in order to obtain a silver halide emulsion layer having a sol fraction of 10% by mass or less, (1) adjustment of the amount of the crosslinking agent and the crosslinking conditions, (2) hydrophilicity that does not react with the hydrophilic binder that reacts with the crosslinking agent. The amount can be controlled by the above three methods, in which a hydrophilic binder is mixed, and (3) a hydrophilic binder having a low molecular weight that can remain water-soluble even when reacted with a crosslinking agent is used. The method 1 has a problem in production stability, and the method 2 or 3 is preferably used in the present invention. Whichever method is used, the total hydrophilic binder in the silver halide emulsion layer of the conductive material precursor in the present invention contains 10% or more, preferably 20 to 70%, more preferably 40 to 60% of the sol fraction. To do.

  In the present invention, the crosslinking agent reacts with a plurality of water-soluble binders to increase the molecular weight of the water-soluble binder to make it water-soluble to water-insoluble. The silver halide emulsion layer of the conductive material precursor in the present invention is crosslinked with a crosslinking agent. By crosslinking, the hydrophilic binder contained in the silver halide emulsion layer, that is, the water-soluble binder, becomes insoluble, and the silver halide emulsion layer can remain at the time of development or plating. Examples of the crosslinking agent in the present invention include crosslinking of known water-soluble binders as described in, for example, “Chemical Reaction of Polymer” (Chemical Doujin, 1972 Nobu Okawara), Chapters 2.6.7 and 5.2. An agent can be used. Specific examples of the water-soluble binder crosslinking agent in the present invention include, for example, formaldehyde, N-methylol compounds (for example, N-methylol urea, N-methylol melamine, N-methylol ethylene urea, and initial contractions thereof), di Aldehydes (eg glyoxal, glutaraldehyde, succinaldehyde, etc.), various epoxy compounds (eg glycerol polyglycidyl ether, sorbitol polyglycidyl ether), activated vinyl compounds (eg bis (vinylsulfonyl) methane, bis (vinylsulfonylmethyl) ether) Japanese Patent Publication No. 44-29622, Japanese Patent Publication No. 47-8736, Japanese Patent Publication No. 48-74832, Japanese Patent Publication No. 49-24435, Japanese Patent Publication No. 51-44164, Japanese Patent Publication No. 53-41221, US Patent 4,173 481, and compounds described in U.S. Patent 4,323,646, etc.), quinones (e.g., p- quinone, etc.), etc. s- triazine (e.g. 2,4-dichloro-6-hydroxy-s-triazine), and the like. In addition, compounds described in Chapter 2 of “The theory of Photographic Process 4th edition (Eastman Kodak Company 1977 TH James)” can also be used.

  As the hydrophilic binder in the silver halide emulsion layer of the conductive material precursor used in the present invention, a hydrophilic binder capable of reacting with a crosslinking agent of the hydrophilic binder is used. The hydrophilic binder with which the crosslinking agent can react varies depending on the crosslinking agent to be used. For example, proteins such as gelatin, casein and albumin, polysaccharides such as polyvinyl alcohol (PVA) and starch, cellulose and its derivatives, polyvinylamine, chitosan , Polylysine, polyacrylic acid, maleic anhydride and vinyl sulfonic acid copolymer, maleic anhydride and styrene copolymer, itaconic acid and vinyl sulfonic acid copolymer, itaconic acid and styrene copolymer, alginic acid In particular, gelatin is preferably used. Further, a plurality of types of hydrophilic binders that can react with these crosslinking agents can be used. In addition, a crosslinking agent is preferably used in 0.1 to 10 weight% with respect to the dry total weight of the hydrophilic binder which reacts with these.

  In the second method for controlling the sol fraction in the present invention, a hydrophilic binder that does not react with the crosslinking agent is also used as the hydrophilic binder in addition to the hydrophilic binder that can react with the crosslinking agent of the hydrophilic binder. The hydrophilic binder that does not react with the crosslinking agent of the hydrophilic binder varies depending on the type of the crosslinking agent (for example, when an epoxy compound is used as the crosslinking agent, the hydrophilic binder having a carboxylic acid group such as polyacrylic acid is an epoxy compound) For example, polyvinyl pyrrolidone (PVP), polyethylene glycol, polyvinyl methyl ether, polystyrene sulfonic acid, polyvinyl sulfate, diallyldimethylammonium chloride polymer, diallyldimethylammonium chloride-sulfur dioxide Examples thereof include a hydrophilic binder having no reactive group such as a copolymer and a hydrophilic binder having a reactive group blocked like phthalated gelatin. In the present invention, these hydrophilic binders that do not react with the crosslinking agent are used by mixing them in an amount sufficient to obtain a preferable sol fraction with the hydrophilic binder that reacts with the crosslinking agent. The preferred amount used varies depending on the type and amount of the crosslinking agent, the type of hydrophilic binder that reacts with the crosslinking agent, etc., but preferably 7% or more, more preferably 15 to 75 of the hydrophilic binder. %contains. In order to achieve the object of the present invention, the molecular weight of the hydrophilic binder that does not react with the crosslinking agent is preferably 80,000 or less.

  In the third method for controlling the sol fraction in the present invention, a hydrophilic binder having a relatively low molecular weight is used. As the kind of the low molecular weight hydrophilic binder, in addition to gelatin, either a hydrophilic binder that reacts with a crosslinking agent or a hydrophilic binder that does not react can be used. However, in order to achieve the object of the present invention, the molecular weight is 20000 or less, preferably 12000. The following hydrophilic binder is preferably used. These hydrophilic binders having a molecular weight of 20000 or less are also used by mixing them with a hydrophilic binder having a large molecular weight in an amount sufficient to obtain a preferable sol fraction. The preferred amount used varies depending on the type and amount of the crosslinking agent, the type of hydrophilic binder that reacts with the crosslinking agent, etc., as well as the hydrophilic binder that does not react with the crosslinking agent, but preferably 7 of the hydrophilic binders. % Or more, more preferably 15 to 60%

  In the present invention, if the total amount of the binder of the hydrophilic polymer contained in the silver halide emulsion layer is small, the coating property is adversely affected, and stable silver halide grains cannot be obtained. Decreases. The mass ratio (total silver amount / total hydrophilic binder amount) to the preferred total hydrophilic binder is 0.8 or more with respect to the total total silver amount (silver equivalent) of the photosensitive silver halide and the non-photosensitive silver salt, More preferably, it is 1.2-3.

  The silver halide emulsion layer of the conductive material precursor used in the present invention may contain a polymer latex as a water-insoluble polymer in addition to the hydrophilic binder. As the polymer latex, various known latexes such as homopolymers and copolymers can be used. Homopolymers include vinyl acetate, vinyl chloride, styrene, methyl acrylate, butyl acrylate, methacrylonitrile, butadiene, and isoprene. Copolymers include ethylene / butadiene, styrene / butadiene, and styrene / p-methoxystyrene. , Styrene / vinyl acetate, vinyl acetate / vinyl chloride, vinyl acetate / diethyl maleate, methyl methacrylate / acrylonitrile, methyl methacrylate / butadiene, methyl methacrylate / styrene, methyl methacrylate / vinyl acetate, methyl methacrylate / vinylidene chloride, methyl acrylate / acrylonitrile , Methyl acrylate / butadiene, methyl acrylate / styrene, methyl acrylate / vinyl acetate, acrylic acid / butyl acrylate, methyl Acrylate-vinyl chloride, butyl acrylate-styrene and the like. The average particle size of the polymer latex used in the present invention is preferably 0.01 to 1.0 μm, more preferably 0.05 to 0.8 μm. Even when a polymer latex is used, the amount used is preferably 20% or less, preferably 10% or less of the hydrophilic binder.

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

  If necessary, the conductive material precursor in the present invention may be provided with a backing layer or an overlayer on the silver halide emulsion layer on the opposite side of the support from the silver halide emulsion layer.

  As the conductive material precursor, it is preferable to use a non-sensitizing dye or pigment having an absorption maximum in the photosensitive wavelength region of the silver halide emulsion layer as a halation for improving image quality or an irradiation prevention agent. An antihalation agent can be contained in the undercoat layer or backing layer between the silver halide emulsion layer and the support. An irradiation inhibitor is preferably contained in the silver halide emulsion layer. The amount added may vary widely as long as the desired effect is obtained, but when it is contained in the backing layer, for example, as an antihalation agent, it is desirably in the range of about 20 mg to about 1 g per square meter, preferably The optical density at the maximum absorption wavelength is 0.5 or more.

  The conductive material precursor used in the present invention is an exposure by adhering a transparent original having an arbitrary fine line pattern such as a mesh pattern and the conductive material precursor, or an argon laser, a He-Ne laser, a red semiconductor laser, An image is formed by scanning and exposing an arbitrary fine line pattern with an image setter using a light emitting diode, an infrared semiconductor laser, or the like.

  In the present invention, after the conductive material precursor is exposed, development processing is performed. In the present invention, the development processing can be performed by a normal development processing technique used for silver salt photographic film, photographic paper, printing plate-making film, photomask emulsion mask and the like. The developer is not particularly limited, but PQ developer, MQ developer, MAA developer, and the like can also be used. For example, Gekol, MRA-CD1001 manufactured by Mitsubishi Paper Industries, CN-16, CR manufactured by Fuji Film Co., Ltd. -56, CP45X, FD-3, papitol, LD745, LD835, developers such as C-41, E-6, RA-4, D-19, D-72, RA2000 manufactured by KODAK, and D-85 A lith developer such as can be used.

  In the present invention, it is preferable to perform a stop process after the development process. Stopping treatment is not impossible only by washing with water, but an acidic stopping solution is preferably used. A preferable stop solution is a stop solution described in “Photochemistry” (written by Sakurai, Photographic Industry Publishing Co., Ltd.) p305.

  In the present invention, after the development and stop processing, fixing processing is performed. Fixing is performed for the purpose of removing and stabilizing the unexposed silver salt. As the fixing solution in the present invention, a known silver salt photographic film, photographic paper, printing plate-making film, photomask emulsion mask and the like can be used. A preferable fixing solution includes the fixing solution described in “Photochemistry” (written by Sakurai, Photographic Industry Publishing Co., Ltd.) p321. It is also preferable to perform a fixing treatment with a fixing solution containing no thiosulfate, for example, using an alkanolamine as a desilvering agent. In addition, a hardening fixer containing a hardening agent such as an aluminum salt may be used as the fixer. Further, an oxidizing agent such as a bleach-fixing agent containing EDTA ferric salt may be used.

  In the present invention, a plating treatment can also be performed for the purpose of imparting higher conductivity to the developed silver portion formed by the exposure and development processing. In the present invention, for the plating treatment, electroless plating (chemical reduction plating or displacement plating), electrolytic plating, or both electroless plating and electrolytic plating can be used.

  For the electroless plating in the present invention, known electroless plating techniques such as electroless nickel plating, electroless cobalt plating, electroless gold plating, silver plating, etc. can be used. In order to obtain transparency, electroless copper plating is preferably performed.

  The electroless copper plating solution in the present invention includes copper sources such as copper sulfate and copper chloride, reducing agents such as formalin, glyoxylic acid, potassium tetrahydroborate, and dimethylamine borane, EDTA, diethylenetriaminepentaacetic acid, Rochelle salt, glycerol, Soerythritol, Adenyl, D-mannitol, D-sorbitol, dulcitol, iminodiacetic acid, t-1,2-cyclohexanediaminetetraacetic acid, 1,3-diaminopropan-2-ol, glycol ether diamine, triisopropanolamine, tri It contains a copper complexing agent such as ethanolamine, a pH adjusting agent such as sodium hydroxide, potassium hydroxide and lithium hydroxide. In addition, polyethylene glycol, yellow blood salt, bipyridyl, o-phenanthroline, neocuproine, thiourea, cyanide, and the like can also be added as additives for improving bath stability and plating film smoothness. The plating solution is preferably aerated to increase stability.

  As described above, various complexing agents can be used in electroless copper plating. However, depending on the type of complexing agent, copper oxide co-deposits, greatly affecting conductivity, or with copper ions such as triethanolamine. It is known that a complexing agent having a low complex stability constant tends to precipitate copper, making it difficult to produce a stable plating solution or plating replenisher. Therefore, the complexing agents usually used industrially are limited, and in the present invention, the selection of the complexing agent is particularly important as the composition of the plating solution for the same reason. Particularly preferable complexing agents include EDTA and diethylenetriaminepentaacetic acid having a large stability constant of a copper complex. Examples of the plating solution using such a preferable complexing agent include a high-temperature type used for producing printed circuit boards. There is electroless copper plating. The method of high-temperature type electroless copper plating is described in detail in “Electroless plating basics and applications” (ed. In high-temperature type plating, the treatment is usually performed at 60 to 70 ° C., and the treatment time varies depending on whether or not the electrolytic plating is performed after the electroless plating. Usually, the electroless plating treatment is performed for 1 to 30 minutes, preferably 3 to 20 minutes. By doing so, the object of the present invention can be achieved.

  In the present invention, when electroless plating other than copper is performed, for example, a method described in Plating Technology Guidebook (Tokyo Sheet Metal Cooperative Technical Committee, 1987) p406 to 432 can be used.

  In the present invention, electrolytic plating can be applied in addition to electroless plating. Various plating methods such as copper plating, nickel plating, zinc plating, cadmium plating, tin plating, and alloy plating are known as electroplating. To ensure transparency and conductivity at low cost as with electroless plating It is preferable to use copper plating. As the copper plating method, any of the known methods such as copper sulfate plating, copper borofluoride plating, copper cyanide plating, and copper pyrophosphate plating can be used. Plating is preferably used. Details of these electroplating methods are described in, for example, “Plating Technology Guidebook” (edited by the Technical Committee of Tokyo Sheet Metal Cooperative Association, 1987) p75-112.

  In the present invention, the metal silver portion can be activated with a solution containing palladium for the purpose of promoting electroless plating before the plating treatment. Palladium may be in the form of a divalent palladium salt or a complex salt thereof, or may be metallic palladium. However, it is preferable to use a palladium salt or a complex salt thereof in view of the stability of the liquid and the stability of the treatment.

  In the present invention, after the plating treatment, an oxidation treatment can also be performed. As the oxidation treatment, known methods using various oxidizing agents can be used. In the oxidation treatment liquid, various aminopolycarboxylic acid iron salts such as EDTA iron salt, DTPA iron salt, 1,3-PDTA iron salt, β-ADA iron salt, BAIDA iron salt, dichromate, persulfate, etc. Salts, permanganates, red blood salts, and the like can be used, but it is preferable to use iron aminopolycarboxylate that is low in environmental burden and safe. The amount of the oxidizing agent used is 0.01 to 1 mol / L, preferably 0.1 to 0.3 mol / L. In addition, known accelerators such as bromides, iodides, guanidines, quinones, witz radicals, aminoethanethiols, thiazoles, disulfide cages, and heterocyclic mercaptos can be used.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but it is needless to say that the present invention is not limited by this description. Unless otherwise specified,% means mass%.

  In order to produce the precursor used in the present invention, a polyethylene terephthalate film having an undercoat layer containing vinylidene chloride and having a thickness of 100 μm was used as a transparent support. A backing layer having the following composition was coated on this support.

<A backing layer composition / 1m ² per>
2g of gelatin
Amorphous silica matting agent (average particle size 5μm) 20mg
Surfactant (S-1) 400mg

  The silver halide emulsion was prepared by a general double jet mixing method for photographic silver halide emulsions. This silver halide emulsion was prepared such that silver chloride was 40 mol% and silver bromide 60 mol%, and the average grain size was 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 1 g of gelatin per 3 g of silver.

  Subsequently, a hydrophilic binder was added to the silver halide emulsion obtained on the opposite side of the backing layer on the backing layer-coated support, and the following formulations a to h and comparative silver halide emulsions i to k were used. A silver halide emulsion layer was coated.

<Silver halide emulsion layer composition a / m ² >
2.7 g of gelatin
PVP K30 (average molecular weight 60000) 0.3 g
Silver halide emulsion 3g silver equivalent Surfactant (S-1) 20mg
1-phenyl-5-mercaptotetrazole 3.0 mg
Glyoxal (40% aqueous solution) 50mg

<Silver halide emulsion layer composition b / 1 m ² >
2.4g gelatin
PVP K30 0.6g
Silver halide emulsion 3g silver equivalent Surfactant (S-1) 20mg
1-phenyl-5-mercaptotetrazole 3.0 mg
Glyoxal (40% aqueous solution) 50mg

<Per silver halide emulsion layer composition c / 1 m ² >
2.1g gelatin
PVP K30 0.9g
Silver halide emulsion 3g silver equivalent Surfactant (S-1) 20mg
1-phenyl-5-mercaptotetrazole 3.0 mg
Glyoxal (40% aqueous solution) 50mg

<Silver halide emulsion layer composition d / 1 m ² >
Gelatin 1.6g
PVP K30 1.4g
Silver halide emulsion 3g silver equivalent Surfactant (S-1) 20mg
1-phenyl-5-mercaptotetrazole 3.0 mg
Glyoxal (40% aqueous solution) 50mg

<Silver halide emulsion layer composition e / m ² >
Gelatin 1.4g
PVP K30 1.6g
Silver halide emulsion 3g silver equivalent Surfactant (S-1) 20mg
1-phenyl-5-mercaptotetrazole 3.0 mg
Glyoxal (40% aqueous solution) 50mg

<Silver halide emulsion layer composition f / 1 m ² >
Gelatin 1.2g
PVP K30 1.8g
Silver halide emulsion 3g silver equivalent Surfactant (S-1) 20mg
1-phenyl-5-mercaptotetrazole 3.0 mg
Glyoxal (40% aqueous solution) 50mg

<Silver halide emulsion layer composition per g / m ² >
Gelatin 0.9g
PVP K30 2.1g
Silver halide emulsion 3g silver equivalent Surfactant (S-1) 20mg
1-phenyl-5-mercaptotetrazole 3.0 mg
Glyoxal (40% aqueous solution) 50mg

<Silver halide emulsion layer composition h / 1 m ² >
Gelatin 1.4g
1.6 g of polyacrylic acid (average molecular weight 50000)
Silver halide emulsion 3g silver equivalent Surfactant (S-1) 20mg
1-phenyl-5-mercaptotetrazole 3.0 mg
Glyoxal (40% aqueous solution) 50mg

<Comparative silver halide emulsion layer composition i / 1 m ² >
3g gelatin
Silver halide emulsion 3g silver equivalent Surfactant (S-1) 20mg
1-phenyl-5-mercaptotetrazole 3.0 mg
Glyoxal (40% aqueous solution) 50mg

<Comparative silver halide emulsion layer composition per j / 1 m ² >
1g of gelatin
Silver halide emulsion 3g silver equivalent Surfactant (S-1) 20mg
1-phenyl-5-mercaptotetrazole 3.0 mg
Glyoxal (40% aqueous solution) 50mg

<Comparative silver halide emulsion layer composition per k / 1 m ² >
Gelatin 1.4g
1.6 g of polyacrylic acid (average molecular weight 50000)
Silver halide emulsion 3g silver equivalent Surfactant (S-1) 20mg
1-phenyl-5-mercaptotetrazole 3.0 mg
EX313 (Nagase Chemtex: Epoxy crosslinking agent) 50mg

In order to measure the sol fraction of the conductive material precursor thus obtained, the backing layer of the conductive material precursor was removed by washing with warm water to prepare a sample for sol fraction measurement, which was ion-exchanged at 40 ° C. After immersing in water for 1 hour and drying, the sol fraction was determined from the mass change. For the sol fraction measurement, a total of 0.1 m ² was used as a sample.

  Next, in order to obtain a conductive material, a transparent original with a mesh pattern having a fine line width of 20 μm and a lattice spacing of 250 μm is closely adhered to the conductive material precursor through a resin filter that cuts light of 400 nm or less with a contact printer using a mercury lamp as a light source. And exposed.

  Subsequently, after dipping in Gekkol developer (manufactured by Mitsubishi Paper Industries Co., Ltd.) at 20 ° C. for 90 seconds, it was then immersed in a 2% acetic acid solution at 20 ° C. for 30 seconds to stop treatment, and further a diamond fix solution (manufactured by Mitsubishi Paper Industries Co. ) At 20 ° C. for 180 seconds to obtain conductive materials 1 to 8 and comparative conductive materials 9 to 11.

  The surface resistivity of the transparent conductive material on which the mesh-patterned silver thin film obtained as described above was formed was measured according to JIS K 7194 using a Loresta-GP / ESP probe manufactured by Dia Instruments Co., Ltd. . Moreover, the total light transmittance was measured.

Furthermore, the obtained conductive material was cut into A4 size, immersed in a 0.001 mol / L PdCl ₂ aqueous solution at 20 ° C. for 10 seconds, and then subjected to electroless plating using the following plating solution. The copper plating treatment was performed at 70 ° C. for 10 minutes, and the plating solution was aerated during that time. The surface resistivity of the transparent conductive material thus obtained was measured. The results obtained are summarized in Table 1.

<Copper plating solution>
10 g of copper sulfate pentahydrate
EDTA · 2Na 40g
Formalin (37%) 3ml
Sodium hydroxide 9g
Bipyridyl 0.01g
Polyethylene glycol 0.01g
Water was added to make 1L.
Adjust to pH = 12.2.

  From Table 1, it can be seen that a conductive material using a conductive material precursor having a sol fraction of 10% or more can obtain a high surface resistivity. Further, it is understood that the sol fraction is preferably 20% or more, and more preferable results can be obtained at 40 to 60%. Further, it can be seen that the comparative sample in which gelatin as a hydrophilic binder is reduced is not efficient in plating, and fogging is generated, so that the change in the total light transmittance before and after plating is large. It can also be seen that if the sol fraction increases excessively and exceeds 60%, the conductivity is adversely affected. Further, when the conductive material 8 and the comparative conductive material 11 are compared, it can be seen that the sol fraction is different due to different crosslinking agents even in the same hydrophilic binder configuration, and as a result, the surface resistivity is greatly different. Therefore, the kind of the hydrophilic binder is not important, and the importance of being within the preferable sol fraction range can be understood.

  Conductive materials 12 to 14 were obtained in the same manner as in Example 1 except that the following silver halide emulsion formulations 1 to n were used as the silver halide emulsion layer. This was evaluated in the same manner as in Example 1, and the results shown in Table 2 were obtained.

<Silver halide emulsion layer composition per 1 m ² >
Gelatin 1.4g
PVP K60 (average molecular weight 350,000) 1.6 g
Silver halide emulsion 3g silver equivalent Surfactant (S-1) 20mg
1-phenyl-5-mercaptotetrazole 3.0 mg
Glyoxal (40% aqueous solution) 50mg

<Silver halide emulsion layer composition per m / 1 m ² >
Gelatin 1.4g
Polyvinyl acrylic acid (average molecular weight 100,000) 1.6g
Silver halide emulsion 3g silver equivalent Surfactant (S-1) 20mg
1-phenyl-5-mercaptotetrazole 3.0 mg
Glyoxal (40% aqueous solution) 50mg

<Silver halide emulsion layer composition per n / 1 m ² >
Gelatin 1.4g
GANTREZ ES425 (copolymer average molecular weight of vinyl methyl ether and maleic anhydride 120,000: manufactured by ISP) 1.6 g
Silver halide emulsion 3g silver equivalent Surfactant (S-1) 20mg
1-phenyl-5-mercaptotetrazole 3.0 mg
Glyoxal (40% aqueous solution) 50mg

  From Table 2, it is understood that the hydrophilic binder that does not react with the crosslinking agent preferably has a lower molecular weight, and that the binder having a molecular weight of 100,000 or more has a relatively low surface resistivity.

  Instead of the silver halide emulsion formulation used in Example 1, the following silver halide emulsion formulation o to rq and comparative silver halide emulsion formulations s and t were used, and this was performed in the same manner as in Example 1. As a result of the evaluation, it was as shown in Table 3.

<Silver halide emulsion layer composition o / m ² >
Gelatin 1.4g
Low molecular gelatin (average molecular weight 3000) 1.6g
Silver halide emulsion 3g silver equivalent Surfactant (S-1) 20mg
1-phenyl-5-mercaptotetrazole 3.0 mg
Glyoxal (40% aqueous solution) 50mg

<Silver halide emulsion layer composition per p / 1 m ² >
2.7 g of gelatin
Low molecular gelatin (average molecular weight 3000) 0.3g
Silver halide emulsion 3g silver equivalent Surfactant (S-1) 20mg
1-phenyl-5-mercaptotetrazole 3.0 mg
Glyoxal (40% aqueous solution) 50mg

<Silver halide emulsion layer composition q / 1 m ² >
Gelatin 1.4g
Low molecular gelatin (average molecular weight 10,000) 1.6g
Silver halide emulsion 3g silver equivalent Surfactant (S-1) 20mg
1-phenyl-5-mercaptotetrazole 3.0 mg
Glyoxal (40% aqueous solution) 50mg

<Silver halide emulsion layer composition r / 1 m ² >
Gelatin 1.4g
1.6 g of polyacrylic acid (average molecular weight 15000)
Silver halide emulsion 3g silver equivalent Surfactant (S-1) 20mg
1-phenyl-5-mercaptotetrazole 3.0 mg
EX313 (Nagase Chemtex) 50mg

<Comparative silver halide emulsion layer composition per s / 1 m ² >
Gelatin 2.85g
Low molecular gelatin (average molecular weight 3000) 0.15g
Silver halide emulsion 3g silver equivalent Surfactant (S-1) 20mg
1-phenyl-5-mercaptotetrazole 3.0 mg
Glyoxal (40% aqueous solution) 50mg

<Comparative silver halide emulsion layer composition per t / m ² >
Gelatin 1.4g
1.6g polyacrylic acid (average molecular weight 30000)
Silver halide emulsion 3g silver equivalent Surfactant (S-1) 20mg
1-phenyl-5-mercaptotetrazole 3.0 mg
EX313 (Nagase Chemtex) 50mg

  From Table 3, when a hydrophilic binder having a molecular weight of 20000 or less is used, the sol fraction can be kept high and a high surface resistivity can be obtained even with a hydrophilic binder that reacts with a crosslinking agent for gelatin. I understand.

Claims (2)

In a conductive material precursor containing at least one silver halide emulsion layer on a support, the conductive material precursor does not have a physical development nucleus layer, and the total hydrophilicity in the silver halide emulsion layer A conductive material precursor having a sol fraction of 10% by mass or more of a binder.   The silver halide emulsion layer is cross-linked by a cross-linking agent, and the hydrophilic binder contained in the silver halide emulsion layer is non-reactive with the hydrophilic binder reactive with the cross-linking agent. The conductive material precursor according to claim 1, wherein the conductive material precursor is a mixture of binders.