JP5281266B2 - Method for producing conductive material precursor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a conductive material precursor capable of obtaining a conductive material with high conductivity. <P>SOLUTION: In the manufacturing method of the conductive material precursor having a physical development nucleus layer and a silver halide emulsion layer in that order on a support body, a coated object after having coated liquid coated and dried on the support body for providing a physical development nucleus layer is put under heating treatment, and then, at least a silver halide emulsion layer is set coated as an upper layer of the physical development nucleus layer. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

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. 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 salt 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 is 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 having a physical development nucleus layer and a silver halide emulsion layer at least in this order on the support, from the side closer to the support , a hydrophilic polymer is provided between the support and the physical development nucleus layer. A base layer containing a cross-linking agent, or a physical development nucleus layer containing a hydrophilic polymer and a cross-linking agent, and a coating solution for applying a physical development nucleus layer on a support is coated and dried. A method for producing a conductive material precursor, comprising heating at 30 to 60 ° C. for 1 to 15 days , and then coating at least a silver halide emulsion layer as an upper layer of a physical development nucleus layer.

  By the above method, a method for producing a conductive material precursor capable of obtaining a conductive material having high conductivity is obtained. Moreover, the manufacturing method of the electroconductive material precursor which has sufficient electroconductivity without impairing light transmittance is obtained.

  As the support used for the conductive material precursor of the present invention, plastic, glass, rubber, ceramics and the like are preferably used. In the case of producing a transparent conductive substrate, a material such as plastic or glass that has transparency in the visible region and has a total light transmittance of 60% or more is preferable. Among plastics, a flexible resin film is preferably used because it is excellent in handleability. Specific examples of the resin film used for the support of the present invention include polyester resins such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), acrylic resins, epoxy resins, fluororesins, silicone resins, polycarbonate resins, Examples thereof include resin films having a thickness of 50 to 300 μm made of acetate resin, triacetate resin, polyarylate resin, polyvinyl chloride, polysulfone resin, polyether sulfone resin, polyimide resin, polyamide resin, polyolefin resin, cyclic polyolefin resin and the like. Examples of the glass include conductive glass such as NESA glass and ITO glass, soda lime glass, non-alkali glass (Corning 7059 glass) and the like. When plastic is used as the support, it is preferable to provide an easy-adhesion layer such as vinylidene chloride or polyurethane on the support, and the surface of the support is corona discharge treatment, ultraviolet treatment, high frequency treatment, glow discharge treatment, active plasma. Surface activation treatment such as treatment or laser treatment may be performed. When glass is used as the support, it is preferable to provide an easy-adhesion layer such as a metal oxide layer such as colloidal silica or titanium oxide, and then heat-treat at 150 to 500 ° C.

  The conductive material precursor of the present invention has a base layer on the support or the easy-adhesion layer for the purpose of enhancing the adhesion between the support and the silver image and for supporting the physical development nuclei on the support. It is preferable to provide it. The base layer is a layer mainly containing a hydrophilic polymer. Here, the main body means that the hydrophilic polymer is contained in an amount of 50% by mass or more based on the total solid content of the base layer. Examples of the hydrophilic polymer for the base layer include proteins, cellulose compounds, sugar derivatives, styrene-butadiene copolymers and the like. Among them, proteins are preferable, and proteins used for the base layer include gelatin, albumin, casein, and these. Is preferred. The base layer may contain a surfactant, a dye, a cross-linking agent, and the like as other components. The content of protein in the base layer is preferably 5 to 500 mg per square meter, particularly preferably 10 to 300 mg.

  The conductive material precursor of the present invention has a physical development nucleus layer and a silver halide emulsion layer at least in this order on the support from the side close to the support. 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 the physical development nuclei in the physical development nuclei layer is suitably about 0.1 to 10 mg per square meter in solid content.

  The physical development nucleus layer can contain a hydrophilic polymer as a binder. As described above, when the base layer is provided on the support or the easy-adhesion layer, the physical development nucleus layer may not contain a hydrophilic polymer as a binder, but when the base layer is not provided, The development nucleus layer preferably contains a hydrophilic polymer as a binder. The addition amount of the hydrophilic polymer is preferably about 10 to 500% by mass with respect to the physical development nucleus. As the hydrophilic polymer, gelatin, gum arabic, cellulose, albumin, casein, sodium alginate, various starches, polyvinyl alcohol, polyvinyl pyrrolidone, polyacrylamide, a copolymer of acrylamide and vinyl imidazole, and the like can be used. Preferred hydrophilic polymers are proteins such as gelatin, albumin and casein.

  The coating solution containing physical development nuclei preferably contains a crosslinking agent. Examples of the crosslinking agent include inorganic compounds such as chromium alum, aldehydes such as formalin, glyoxal, malealdehyde and glutaraldehyde, N-methylol compounds such as urea and ethylene urea, mucochloric acid, and 2,3-dihydroxy-1 Aldehyde equivalents such as 1,4-dioxane, 2,4-dichloro-6-hydroxy-s-triazine salts, compounds having an active halogen such as 2,4-dihydroxy-6-chloro-triazine salts, divinyl sulfone Divinyl ketone, 1,3,5-triacryloylhexahydro-1,3,5-triazine, compounds having two or more active three-membered ethyleneimino groups or epoxy groups in the molecule, polymer hard One or more kinds of cross-linking agents (hardeners) for various proteins such as dialdehyde starch as filming agents Preferably it contains. Among these cross-linking agents, dialdehydes such as glyoxal, glutaraldehyde, 3-methylglutaraldehyde, succinaldehyde, and adipaldehyde are preferable, and glutaraldehyde is more preferable. The crosslinking agent is preferably contained in a coating solution containing physical development nuclei in an amount of 0.0001 to 1 mol, based on 1 g of protein contained in the base layer and / or the physical development nuclei layer, and particularly 0.001 to 0.001. One mole is preferred.

  In the present invention, from the viewpoint of enhancing the adhesion between the support and the silver image, it is extremely preferable that the physical development nuclei are supported on a crosslinked layer provided on the support. Therefore, when the conductive material precursor does not have a base layer, it is preferable that the coating liquid containing physical development nuclei contains both the hydrophilic polymer and the crosslinking agent. On the other hand, when the conductive material precursor has a base layer, the cross-linking agent may contain a coating solution for coating the base layer, or crosslink before applying a coating solution containing physical development nuclei. Although the coating agent alone may be applied alone, the most preferred embodiment in the present invention is that the coating solution containing physical development nuclei contains a crosslinking agent, and this is applied onto the base layer, whereby the crosslinking agent is applied inside the base layer. The physical development nuclei are supported on the cross-linked base layer. Examples of methods for applying a coating solution containing physical development nuclei include various application methods such as dip coating, slide coating, curtain coating, bar coating, air knife coating, roll coating, gravure coating, and spray coating.

  In the method for producing a conductive material precursor of the present invention, the coated product after the physical development nucleus layer is applied and dried is heated. It is extremely preferable that the conductive material precursor has physical development nuclei supported on the cross-linked layer provided on the support as described above. However, as a result of careful experiments by the inventor, compared with the conductivity of a conductive material precursor in which at least a silver halide emulsion layer is coated on a physical development nucleus layer supported on a film in which an unreacted crosslinking agent is present. The conductive development core layer is coated and dried, and the coated product is heated, and at least a silver halide emulsion layer is coated on the physical development nucleus layer carried on the film with reduced unreacted crosslinking agent. It has been found that the conductivity of the conductive material precursor is dramatically improved.

  As described in the aforementioned patent document, a conductive material precursor having at least a physical development nucleus layer and a silver halide emulsion layer on a support is conventionally coated with a coating solution for providing a physical development nucleus layer. Thereafter, it was generally produced by a production method in which a coating solution for forming a silver halide emulsion layer was applied without heating. On the other hand, in the present invention, a coating solution for providing a physical development nucleus layer is applied on a support and dried to provide a physical development nucleus layer, and this coating is heated, and then as an upper layer of the physical development nucleus layer. At least a silver halide emulsion layer is coated. The temperature during the heating treatment is preferably 30 to 50 ° C., and the period is preferably 3 to 15 days. If the temperature is lower than this temperature, the effect of improving the conductivity is difficult to obtain, and even if it is high, the effect of further improvement is difficult to obtain. If the heating treatment period is shorter than this, it is difficult to obtain the effect of improving the conductivity, and even if it is longer than this, it is difficult to obtain a further improvement effect.

  In the present invention, if necessary, an intermediate layer may be provided between the physical development nucleus layer coated with a coating solution containing physical development nuclei and the silver halide emulsion layer. The conductive material precursor produced according to the present invention is imagewise exposed, and after allowing a soluble silver complex salt forming agent and a reducing agent to act in an alkali treatment solution, the conductive material precursor is washed with warm water or the like to be conductive. The above-described intermediate layer is suitable for promoting the removal of the layer on the physical development nucleus that is no longer necessary. The intermediate layer is a layer mainly containing a hydrophilic polymer. As the hydrophilic polymer here, any polymer can be selected as long as it easily swells with a developing solution (alkali processing solution) and allows the developing solution to easily penetrate into the underlying physical development nucleus. Moreover, a main body means containing 50 mass% or more of hydrophilic polymers with respect to the total solid of an intermediate | middle 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 solid content coating amount of the hydrophilic polymer in the intermediate layer is preferably in the range of 3 to 30% by mass with respect to the total binder amount of the silver halide emulsion layer. 10-20 mass% is 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.

  The formation of silver halide emulsion grains used in the silver halide emulsion layer is performed by Research Disclosure Item 17643 (December 1978) and 18716 (November 1979), 308119 (forward mixing, reverse mixing, simultaneous mixing, etc.). (December 1989) can be 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. 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 A group metal element salt or a complex salt 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 binder of the silver halide emulsion layer is preferably a hydrophilic polymer, and examples of the hydrophilic polymer include proteins, cellulose compounds, sugar derivatives, styrene-butadiene copolymers, etc. Among them, proteins are preferable. As the protein, gelatin, albumin, casein or a mixture thereof is preferable. Further, when gelatin is used as the hydrophilic polymer, 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), 308119 (December 1989) or cited.

  Moreover, you may provide a protective layer as needed as an outermost layer furthest from a support body. The protective layer is a layer mainly containing a hydrophilic polymer, like the intermediate layer described above. 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 solid coating amount of the hydrophilic polymer in the protective layer for sufficiently obtaining the effects of the present invention is such that the amount combined with the hydrophilic polymer in the intermediate layer is 20 with respect to the total binder amount of the silver halide emulsion layer. The range of -100 mass% is preferable, and 30-80 mass% is especially preferable.

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

  Further, 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 irradiation inhibitor 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. The irradiation inhibitor is preferably contained in the silver halide emulsion layer. The amount added may vary widely as long as the desired effect can be obtained, but is preferably in the range of about 20 mg to about 1 g per square meter when incorporated in the backing layer as an antihalation agent, for example.

  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 layer 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 forming agents include thiosulfates such as ammonium thiosulfate and sodium thiosulfate, thiocyanates such as sodium thiocyanate and ammonium thiocyanate, sulfites such as sodium sulfite and potassium bisulfite, oxadoridones, 2-mercaptobenzoic acid and its derivatives, cyclic imides such as uracil, alkanolamines, diamines, mesoionic compounds described in JP-A-9-171257, described in US Pat. No. 5,200,294 Such thioethers, 5,5-dialkylhydantoins, alkyl sulfones, and others. H. Examples thereof include compounds described in 474-475 (1977) of The Theory of the Photographic Process, 4th edition, edited by James.

  Next, the reducing agent 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-mentioned soluble silver complex salt forming agent and reducing agent may be contained in the physical development nucleus layer or the base layer, may be contained in the silver halide emulsion layer, or contained in the alkali processing liquid. Furthermore, it can be contained in a plurality of positions. In particular, the above-described soluble silver complex salt forming agent and reducing agent are preferably contained in 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. Application of the alkaline processing liquid for performing silver complex diffusion transfer development of the conductive material precursor obtained in the present invention may be 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, the preferable treatment conditions for the alkaline treatment liquid are suitably adjusted to a temperature of the alkaline treatment liquid of 18 to 22 ° C. 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.

  For the purpose of imparting higher conductivity to the silver image portion formed by the exposure and development process using the conductive material precursor obtained in the present invention, it is also preferable to perform a plating process after the development process. 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 electroless plating, known electroless plating techniques such as electroless nickel plating, electroless cobalt plating, electroless gold plating, and electroless silver plating can be used, but sufficient conductivity and light can be obtained at low cost. In order to obtain permeability, electroless copper plating is preferably performed.

  Electroless copper plating solutions include copper sources such as copper sulfate and copper chloride, reducing agents such as formalin, glyoxylic acid, potassium tetrahydroborate, dimethylamine borane, EDTA, diethylenetriaminepentaacetic acid, Rochelle salt, glycerol, meso-erythritol, Adonitol, D-mannitol, D-sorbitol, dulcitol, iminodiacetic acid, t-1,2-cyclohexanediaminetetraacetic acid, 1,3-diaminopropan-2-oltetraacetic acid, glycol etherdiaminetetraacetic acid, triisopropanolamine, It contains a copper complexing agent such as triethanolamine, 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, 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.

  In the case of performing electroless plating treatment other than copper, for example, the method described in “Plating Technology Guidebook” (Tokyo Sheet Metal Cooperative Technical Committee, 1987) p406 to 432 can be used.

  In addition to electroless plating, electrolytic plating can also be performed. Various plating methods such as copper plating, nickel plating, zinc plating, cadmium plating, tin plating, and alloy plating are known as electrolytic plating. To ensure light transmittance and conductivity at low cost as with electroless plating. It is preferable to use copper plating. As a 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. However, copper sulfate plating, particularly high-throw copper sulfate plating, is easy because of the waste liquid. 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 addition, 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.

In order to obtain the conductive material in the present invention, a polyethylene terephthalate film having a thickness of 100 μm (total light transmittance is 95%) is used as the support, and the base layer is formed so that the gelatin coating amount is 0.15 g / m ^2. It coated on both surfaces of the support body. A backing layer having the following composition was applied to one surface of the base layer 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 surface of the base layer opposite to the side having the backcoat layer, a coating solution containing physical development nuclei made of palladium sulfide prepared as described below was added in a solid content of 0.4 mg / m ^{2 of} palladium sulfide. It was applied and dried. Thereafter, heating treatment was performed under the conditions shown in Table 1.

<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, the coating solution containing the above-mentioned physical development nuclei was applied, and the following intermediate layer, the silver halide emulsion layer and the protective layer described later were simultaneously applied onto the dried physical development nuclei layer using a slide beat coater, and conductive. A functional material precursor was obtained. At this time, the silver halide emulsion layer was coated so that the amount of silver was 2.54 g / m ^2, and Samples 1 to 10 which were conductive material precursors 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 10 as the conductive material precursors thus obtained 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 samples 1 to 10 were subjected to an immersion treatment at 20 ° C. for 60 seconds with an alkali treatment solution (silver complex diffusion transfer developer) having the following composition, then washed with warm water at 40 ° C. 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 Co., Ltd. The results are summarized in Table 1.

  As is apparent from Table 1, a conductive material having high conductivity was obtained from the sample of the present invention in which the coating liquid for the physical development nucleus layer was applied and dried and then heated. Moreover, the electroconductive material obtained by this invention was able to obtain high electroconductivity, without impairing light transmittance. Sample 1A is a sample obtained by adjusting the exposure amount when producing Sample 1 so that the surface resistivity is equivalent to that of the sample of the present invention. As a result, Sample 1A had a wider line width and a reduced total light transmittance.

Claims (1)

In the method for producing a conductive material precursor having a physical development nucleus layer and a silver halide emulsion layer at least in this order on the support, from the side closer to the support , a hydrophilic polymer is provided between the support and the physical development nucleus layer. A base layer containing a cross-linking agent, or a physical development nucleus layer containing a hydrophilic polymer and a cross-linking agent, and a coating solution for applying a physical development nucleus layer on a support is coated and dried. A method for producing a conductive material precursor, comprising heating at 30 to 60 ° C. for 1 to 15 days , and then coating at least a silver halide emulsion layer as an upper layer of a physical development nucleus layer.