JP2008198388A - Method for producing conductive material precursor - Google Patents

Abstract

A method for producing a conductive material precursor capable of obtaining a conductive material having high conductivity is provided.
In a method for producing a conductive material precursor, a coating liquid containing physical development nuclei is coated on a support having a base layer, dried, and at least a silver halide emulsion layer is coated thereon. A method for producing a conductive material precursor, characterized in that the drying temperature during the treatment is 45 ° C. or lower.
[Selection figure] None

Description

  The present invention relates to a conductive material precursor that can be used for applications such as an electronic circuit, an antenna circuit, an electromagnetic wave shielding material, and a touch panel, and a method for producing a conductive material using the same.

  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 the health of the human body cannot be ignored, and it is required to reduce the intensity of the electromagnetic field irradiated to the human body, and various conductive materials have been developed in response to such a demand. ing. 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 conductive materials, a conductive metal such as silver, copper, nickel, or indium is formed on a resin film by sputtering, ion plating, ion beam assist, vacuum deposition, or wet coating. A method of forming a thin film is generally used. However, since these conventional methods are extremely complicated, there has been a problem of high cost and poor productivity.

  Under such circumstances, there has been a demand for a method of forming conductive patterns additively by a highly productive method. Since the silver halide photographic light-sensitive material has a high resolving power and the image is metallic silver, it is expected to be a promising candidate for such an application. For example, International Publication No. 01/51276 (Patent Document 1) discloses silver. There has been proposed a method for producing a conductive material by using a salt photographic light-sensitive material as a conductive material precursor, performing image exposure and development, and then performing metal plating. However, in this method, the silver image serving as a plating catalyst is buried in a hydrophilic binder, and it is not easy to contact with the plating solution, and the catalytic activity due to contamination is reduced, so that the metal plating process is difficult. There was no advantage over existing methods.

  In Japanese Patent Application Laid-Open No. 2004-221564 (Patent Document 2), similarly to Patent Document 1, a conductive pattern is formed by supplying metal to the silver image from the outside by physical development or plating treatment. It is disclosed that the plating efficiency is improved by increasing the / gelatin volume ratio. However, in the method as disclosed in the publication, it is essential to supply metal from the outside. For example, only silver in the silver halide light-sensitive material can obtain the minimum conductivity for performing electroplating. It was difficult.

Similarly, a method using a silver complex diffusion transfer method has also been proposed as a method of using a silver salt photosensitive material as a conductive material precursor, such as International Publication No. 2004/007810 (Patent Document 3). In this method, since the silver image is not covered with a very small amount of binder or substantially covered with the binder, it is easy to contact the plating solution with the silver image, and the minimum conductivity for performing electroplating. It can be said that it is a preferable method from the point which can also be obtained. However, higher electroconductivity has been demanded in order to perform electrolytic plating uniformly and efficiently. Furthermore, in applications such as electromagnetic shielding materials and touch panels, excellent conductivity and light transmission are required, and a method for obtaining a fine metal pattern having sufficient conductivity without impairing light transmission is required. It was.
WO 01/51276 pamphlet (1 page) JP 2004-221564 A (pages 1 to 5) International Publication No. 2004/007810 Pamphlet (1 page)

  Therefore, the objective of this invention is providing the manufacturing method of the electroconductive material precursor which can obtain the electroconductive material with high electroconductivity. It is another object of the present invention to provide a method for producing a conductive material precursor capable of obtaining a conductive material having sufficient conductivity without impairing light transmittance.

The above object of the present invention has been achieved by the following invention.
In the method for producing a conductive material precursor in which a coating liquid containing physical development nuclei is applied to a support having a base layer, dried, and at least a silver halide emulsion layer is coated thereon, drying at the time of drying is performed. The manufacturing method of the electroconductive material precursor characterized by the temperature being 45 degrees C or less.

  By the said method, the manufacturing method of the electroconductive material precursor which can obtain the electroconductive material with high electroconductivity was obtained. Moreover, the manufacturing method of the electroconductive material precursor with sufficient electroconductivity was obtained, without impairing light transmittance.

  In the method for producing a conductive material precursor of the present invention, for example, dip coating, slide coating, curtain coating, bar coating, air knife coating, roll can be applied as a method of applying a coating solution containing physical development nuclei on the base layer. There are various coating methods such as coating, gravure coating, and spray coating. After coating, the coating solution on the base layer is dried in air with controlled temperature and dew point, and wound around the core in a roll shape. The drying temperature in the present invention indicates the dry bulb temperature of air used for drying the coating liquid on the support.

  Conventionally, in the conductive material precursor, the drying temperature at the time of drying after coating the coating liquid containing physical development nuclei is relatively high temperature air of 50 to 60 ° C. from the viewpoint of productivity. Drying was performed under such conditions that it dries quickly. In this method, the binder of the base layer swells due to the influence of coating liquid containing physical development nuclei and high-temperature air, and as a result, part of the coating liquid containing physical development nuclei sinks into the binder. This phenomenon hinders the precipitation of metallic silver on the physical development nuclei in silver complex diffusion transfer. In contrast, the present invention reduces the sinking of the coating liquid containing physical development nuclei into the base layer by setting the drying temperature when drying the coating liquid containing physical development nuclei to 45 ° C. or lower. It is considered that a conductive material having high conductivity can be obtained by forming a silver image layer uniformly on the surface layer of the base layer. A more preferable drying temperature is 30 ° C. or lower, and the lower limit of the drying temperature is preferably 10 ° C. or higher in consideration of the time required for drying. In addition, the dew point of the air used at the time of drying is preferably in the range of minus 20 ° C. to plus 15 ° C., and when air drying is performed, the air blowing speed is preferably 5 to 40 m / second.

  As the physical development nuclei in the conductive material precursor of the present invention, fine particles (having a particle size of about 1 to several tens of nm) made of heavy metals or sulfides thereof are used. Examples thereof include colloids such as gold and silver, metal sulfides obtained by mixing sulfides with water-soluble salts such as palladium and zinc, and silver colloids and palladium sulfide nuclei are preferable. The content of physical development nuclei is suitably about 0.1 to 10 mg per square meter in solid content.

  Examples of coating solutions containing physical development nuclei include inorganic compounds such as chromium alum, formalin, glyoxal, malealdehyde, aldehydes such as glutaraldehyde, N-methylol compounds such as urea and ethylene urea, mucochloric acid, Aldehyde equivalents such as 2,3-dihydroxy-1,4-dioxane, activities such as 2,4-dichloro-6-hydroxy-S-triazine salt and 2,4-dihydroxy-6-chloro-triazine salt Two or more halogen-containing compounds, divinyl sulfone, divinyl ketone, 1,3,5-triacryloylhexahydro-1,3,5-triazine, active three-membered ethyleneimino group or epoxy group in the molecule A cross-linking agent (hardener) for various proteins such as dialdehyde starch as a polymer hardener Or containing two or more. Among these crosslinking agents, dialdehydes such as glyoxal, glutaraldehyde, 3-methylglutaraldehyde, succinaldehyde, and adipaldehyde are preferable, and glutaraldehyde is more preferable. The cross-linking agent is preferably contained in a coating solution containing physical development nuclei in an amount of 0.0001 to 1 mol, particularly 0.001 to 0.1 mol, based on 1 g of protein contained in the following base layer.

  As the support used for the conductive material precursor of the present invention, a support having a base layer is used for the purpose of enhancing the adhesion between the support and the silver image and for supporting the physical development nuclei. Examples of the substrate used for the support include polyester resins such as polyethylene terephthalate, diacetate resins, triacetate resins, acrylic resins, polycarbonate resins, polyvinyl chloride, polyimide resins, cellophane, celluloid and other plastic resin films, glass plates, and the like. It is done.

  For the purpose of enhancing the coatability of the base layer to these substrates, the substrate surface may be subjected to surface activation treatment such as corona discharge treatment, ultraviolet treatment, high frequency treatment, glow discharge treatment, active plasma treatment, and laser treatment. The base layer is a layer mainly containing a binder, and the main body is a layer containing 50% by mass or more of the binder with respect to the total solid content of the base layer. Examples of the binder for the base layer include proteins, cellulose compounds, sugar derivatives, styrene-butadiene copolymers, etc. Among them, proteins are preferable, and proteins used for the base layer include gelatin, albumin, casein, or a mixture thereof. Is preferred. The base layer may contain a surfactant, a dye, a hardener, and the like as other components. The protein content in the base layer is preferably 10 to 300 mg per square meter. Moreover, it is preferable to have an easily bonding layer containing a polyvinylidene chloride, a polyurethane, an acrylic polymer, a polyester polymer, etc. between a support body and a base layer.

  In the present invention, if necessary, an intermediate layer may be provided between the base layer coated with a coating solution containing physical development nuclei and the silver halide emulsion layer. The conductive material precursor of the present invention has a desired pattern having conductivity by exposing imagewise, allowing a soluble silver complex salt forming agent and a reducing agent to act in an alkaline solution, and then washing with warm water or the like. The above-mentioned intermediate layer is suitable for promoting the removability of the layer on the physical development nucleus that is no longer necessary. The intermediate layer is a layer having a hydrophilic polymer as a main binder. As the hydrophilic polymer here, any polymer can be selected as long as it easily swells with the developer and easily penetrates into the underlying physical development nucleus. The term “mainly” means that the hydrophilic polymer is contained in an amount of 50% by mass or more based on the total solid content of the intermediate layer. As the hydrophilic polymer, gelatin, albumin, casein, polyvinyl alcohol, or the like can be used. Particularly preferred hydrophilic polymers are proteins such as gelatin, albumin and casein. In order to sufficiently obtain the effects of the present invention, the binder amount of the intermediate layer is preferably in the range of 3 to 30% by mass, particularly 10 to 20% by mass, based on the total binder amount of the silver halide emulsion layer. preferable.

  In addition, a known photographic additive as described in Research Disclosure Item 17643 (December 1978) and 18716 (November 1979) and 308119 (December 1989) is optionally added to the intermediate layer. It can be included.

  In the conductive material precursor of the present invention, a silver halide emulsion layer is provided as an optical sensor. Techniques used for silver halide photographic films, photographic papers, printing plate-making films, photomask emulsion masks, and the like relating to silver halides can be used as they are.

  For formation of 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. (December 1989) can be used. Of these, the so-called controlled double jet method, which is one of the simultaneous mixing methods and keeps pAg in the liquid phase in which the grains are formed, is preferable from the viewpoint of obtaining silver halide emulsion grains having a uniform particle diameter. 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. There is a preferred range for the halide composition of the silver halide emulsion used in the present invention, and it is preferable to contain at least 80 mol% of chloride.

  In the production of silver halide emulsions, sulfites, lead salts, thallium salts, rhodium salts or complex salts thereof, iridium salts or complex salts thereof, etc., in the process of silver halide grain formation or physical ripening as required, such as VIII Group metal element salts or complex salts thereof may coexist. Further, it can be sensitized by various chemical sensitizers, and methods commonly used in the art such as sulfur sensitization method, selenium sensitization method and noble metal sensitization method can be used alone or in combination. In the present invention, the silver halide emulsion can be dye-sensitized as necessary.

  The ratio of the amount of silver halide and the amount of gelatin contained in the silver halide emulsion layer is such that the mass ratio of silver halide (silver equivalent) to gelatin (silver / gelatin) is 1.2 or more, more preferably 1. 5 or more.

  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) and 308119 (December 1989) or cited.

  Moreover, you may provide a protective layer as needed as an outermost layer furthest from a support body. A protective layer is a layer which uses a hydrophilic polymer as a main binder like the above-mentioned intermediate layer. As the hydrophilic polymer, any polymer can be selected as long as it easily swells in the developer and allows the developer to easily penetrate into the underlying silver halide emulsion layer and the physical development nucleus. Specifically, gelatin, Albumin, casein, polyvinyl alcohol, and the like can be used. Particularly preferred hydrophilic polymers are proteins such as gelatin, albumin and casein. The binder amount of the protective layer for sufficiently obtaining the effects of the present invention is preferably in the range of 20 to 100% by mass with respect to the total binder amount of the silver halide emulsion layer, in combination with the binder of the intermediate layer described above. In particular, 30 to 80% by mass is preferable.

  The protective layer may contain a known photographic additive as described in Research Disclosure Item 17643 (December 1978) and 18716 (November 1979) and 308119 (December 1989) as necessary. It can be included.

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

  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 an antihalation agent or an anti-irradiation agent for improving image quality. The antihalation agent can be contained in an intermediate layer between the silver halide emulsion layer and the support or in a backing layer. An irradiation inhibitor is preferably contained in the silver halide emulsion layer. The addition amount can vary widely as long as the desired effect can be obtained, but for example, when it is contained in the backing layer as an antihalation agent, it is preferably in the range of about 20 mg to about 1 g per square meter.

  Examples of a method for producing a conductive material using the conductive material precursor include formation of a silver thin film having a mesh pattern. In this case, the silver halide emulsion layer is exposed in a reticulated pattern. As an exposure method, a method of exposing the retransmitted original of the reticulated pattern and the conductive material precursor to be exposed, or scanning using various laser beams. There are exposure methods. 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.

  After the exposure, the conductive material is subjected to silver complex diffusion transfer development with an alkaline processing solution, and washed with warm water to remove a layer provided on a physical development nucleus such as a silver halide emulsion layer. This alkaline processing liquid is a liquid used when performing silver complex diffusion transfer development which is physical development processing. As a method for removing the hydrophilic colloid layer provided on the physical development nucleus, there are a method of removing by washing or transferring and peeling to a release paper or the like. There are two methods for removing the water washing: a method of removing hot water using a scrubbing roller or the like while jetting it with a nozzle or the like, and a method of removing hot water by jetting with a nozzle or the like. In addition, the method of transferring and peeling with a release paper or the like is to squeeze the excess alkali processing solution (silver complex salt diffusion transfer developer) on the silver halide emulsion layer in advance with a roller or the like, and the silver halide emulsion layer and the release paper. Is a method in which a silver halide emulsion layer or the like is transferred from a plastic resin film to a release paper and peeled off. As the release paper, water-absorbing paper or non-woven fabric, or paper having a water-absorbing void layer formed of fine pigment such as silica and binder such as polyvinyl alcohol on the paper is used.

  Next, a soluble silver complex salt forming agent, a reducing agent, and an alkali processing solution necessary for silver complex diffusion transfer development will be described. The soluble silver complex salt forming agent is a compound that dissolves silver halide to form a soluble silver complex salt, and the reducing agent is a compound that reduces this soluble silver complex salt to precipitate metallic silver on physical development nuclei. These actions are performed in an alkali treatment solution.

  Soluble silver complex salt forming agents used in the present invention include thiosulfates such as ammonium thiosulfate and sodium thiosulfate, thiocyanates such as sodium thiocyanate and ammonium thiocyanate, and sulfites such as sodium sulfite and potassium hydrogen sulfite. Salts, oxazolidones, 2-mercaptobenzoic acid and derivatives thereof, cyclic imides such as uracil, alkanolamines, diamines, mesoionic compounds described in JP-A-9-171257, US Pat. No. 5,200,294 Thioethers, 5,5-dialkylhydantoins, alkyl sulfones, etc. as described in the specification; H. Examples include compounds described on pages 474 to 475 (1977) of James, The Theory of the Photographic Process, 4th edition.

  Next, the reducing agent used in the present invention will be described. As the reducing agent, a developing agent known in the field of photographic development can be used. For example, hydroquinone, catechol, pyrogallol, methylhydroquinone, chlorohydroquinone and other polyhydroxybenzenes, ascorbic acid and its derivatives, 1-phenyl-4,4-dimethyl-3-pyrazolidone, 1-phenyl-3-pyrazolidone, 1- Examples include 3-pyrazolidones such as phenyl-4-methyl-4-hydroxymethyl-3-pyrazolidone, paramethylaminophenol, paraaminophenol, parahydroxyphenylglycine, paraphenylenediamine, and the like.

  The above-described soluble silver complex salt forming agent and reducing agent may be coated on the support or base layer together with the physical development nuclei, may be added to the silver halide emulsion layer, or in the alkaline processing liquid. It may be contained in more than one position. The above-described soluble silver complex salt forming agent and reducing agent are preferably contained in at least the alkali treatment liquid.

  The content of the soluble silver complex salt forming agent in the alkali processing solution is suitably used in the range of 0.1 to 5 mol per liter of the developer, and the reducing agent is 0.05 to 5 per liter of the developer. It is suitable to use in the range of 1 mole.

  The pH of the alkali treatment liquid is preferably 10 or more, more preferably 11-14. In the present invention, the alkaline processing liquid for silver complex diffusion transfer development can be applied by an immersion method or a coating method. In the immersion method, for example, a conductive material precursor provided with a physical development nucleus and a silver halide emulsion layer is transported while being immersed in an alkaline processing solution stored in a large amount in a tank. For example, about 40 to 120 ml of an alkali treatment solution is applied on a silver halide emulsion layer per square meter.

  In the present invention, it is preferable that the temperature of the alkaline treatment liquid when the alkaline treatment liquid is applied is 18 to 22 ° C. as a preferable embodiment for improving the conductivity. The application time of the alkali treatment liquid is suitably about 20 seconds to 3 minutes. This aspect is particularly suitable in the case of the immersion method.

  In the present invention, for the purpose of imparting higher conductivity to the silver image portion formed by the exposure and development processing, it is also preferable to perform a plating treatment after the 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, and electroless silver plating can be used. Electroless copper plating is preferably performed to obtain the properties and light transmittance.

  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, meso -Erythritol, adonitol, D-mannitol, D-sorbitol, dulcitol, iminodiacetic acid, t-1,2-cyclohexanediamine tetraacetic acid, 1,3-diaminopropan-2-ol tetraacetic acid, glycol ether diamine tetraacetic acid, tri Copper complexing agents such as isopropanolamine and triethanolamine, pH adjusting agents such as sodium hydroxide, potassium hydroxide and lithium hydroxide are contained. 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 stabilization 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, which have a large stability constant of copper complex. Examples of plating solutions using such a complexing agent include high-temperature types used in the production of 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. Preferably it is done.

  When electroless plating treatment other than copper is performed in the present invention, for example, a method described in “Plating Technology Guidebook” (edited by 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. As electrolytic plating, various plating methods such as copper plating, nickel plating, zinc plating, cadmium plating, tin plating, and alloy plating are known. It is preferable to use copper plating in order to ensure light transmission and conductivity at a low cost as with electroless plating. As a copper plating method, any of the known methods such as copper sulfate plating, copper borofluoride plating, copper cyanide plating, copper pyrophosphate plating, etc. 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.

  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.

(Example 1)
In order to obtain the conductive material in the present invention, a polyethylene terephthalate film having a thickness of 100 μm having a gelatin base layer of 0.15 g / m ² on both surfaces was used as a support. A backing layer having the following composition was applied to one side of the support and dried.

<Backcoat layer composition>
Gelatin 2g / m ²
Amorphous silica matting agent (average particle size 5 μm) 20 mg / m ²
Surfactant (S-1) 400 mg / m ²
Dye 1 200 mg / m ²

Next, on the opposite surface of the support having the backing layer, a coating solution containing physical development nuclei made of palladium sulfide prepared as described below has a solid content of palladium sulfide of 0.4 mg / m ² . Then, the air controlled by the dry bulb thermometer was sent and dried at the drying temperatures shown in Table 1. The dew point of the air sent at this time was minus 5 ° C., and the wind speed was 20 m / second.

<Preparation of palladium sulfide sol>
Liquid A Palladium chloride 5g
Hydrochloric acid 40ml
1000ml distilled water
B liquid sodium sulfide 8.6g
1000ml distilled water
Liquid A and liquid B were mixed with stirring, and 30 minutes later, the solution was passed through a column filled with an ion exchange resin to obtain palladium sulfide sol.

<Preparation of coating solution containing physical development nuclei>
50 ml of palladium sulfide sol
4% glutaraldehyde solution 45ml
Surfactant (S-1) 1g
Add water to make a total volume of 2000 ml.

Next, a coating solution containing the above physical development nuclei is applied, and the following intermediate layer, a silver halide emulsion layer and a protective layer described later are simultaneously applied onto the dried base layer using a slide beat coater, and a conductive material. A precursor was obtained. At this time, the silver halide emulsion layer was coated so that the silver amount was 2.54 g / m ² , and Samples 1 to 5 were obtained.

<Interlayer composition>
Gelatin 0.25g / m ²
Surfactant (S-1) 3 mg / m ²

<Preparation of silver halide emulsion>
The silver halide emulsion was prepared by maintaining the pAg at 7.5 by the general double jet mixing method of photographic silver halide emulsions. This silver halide emulsion was prepared such that 90 mol% of silver chloride and 10 mol% of silver bromide had an average particle size of 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. Subsequently, 1.6 g / m ^{2 of} gelatin, 3.0 mg / m ^{2 of} 1-phenyl-5-mercaptotetrazole, and surfactant (S-1) were added to 2.54 g of silver halide emulsion in terms of silver. 20 mg / m ² was added.

<Protective layer composition>
Gelatin 1g / m ²
Amorphous silica matting agent (average particle size 3.5 μm) 15 mg / m ²
Surfactant (S-1) 3 mg / m ²

  Samples 1 to 5, which are conductive material precursors obtained in this way, were passed 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 a mesh pattern with a fine line width of 20 μm and a lattice spacing of 250 μm was used. The transparent original was brought into close contact and exposed.

  The exposed conductive material precursor is subjected to an immersion treatment at 20 ° C. for 60 seconds with an alkali processing solution (silver complex diffusion transfer developer) having the following composition, and then washed with warm water at 40 ° C. to obtain an intermediate layer and a silver halide emulsion. The layer and the protective layer were removed and dried.

<Alkali treatment liquid>
Sodium hydroxide 20g
Hydroquinone 20g
1-phenyl-3-pyrazolidone 2g
Sodium sulfite 30g
N-methylethanolamine 10g
Total volume 1000ml with water
Adjust to pH = 13.

  The surface resistivity of the conductive material on which the mesh pattern 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. Regarding light transmittance, the total light transmittance of the portion of the mesh-patterned silver thin film was measured with a double beam type haze computer manufactured by Suga Test Instruments. The results are summarized in Table 1.

  As is clear from Table 1, a conductive material having high conductivity was obtained from the sample of the present invention in which the coating solution containing physical development nuclei was dried at 45 ° C. or lower. Moreover, the electroconductive material obtained by this invention was able to obtain high electroconductivity, without impairing light transmittance.

Claims (1)

  In the method for producing a conductive material precursor in which a coating liquid containing physical development nuclei is applied to a support having a base layer, dried, and at least a silver halide emulsion layer is coated thereon, drying at the time of drying is performed. The manufacturing method of the electroconductive material precursor characterized by the temperature being 45 degrees C or less.