JP2009146587A - Manufacturing method of conductive material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a conductive material which has a high conductivity and can form a wiring pattern in which a fattening of a wire width of a conductor circuit by an electroless copper plating is limited. <P>SOLUTION: After forming a silver image at least on the one surface of a supporting body, a plating treatment is conducted on the silver image in a first plating bath in which a dissolved oxygen density in the electroless copper plating liquid is 4 ppm or more, and thereafter, a plating treatment is conducted in a second plating bath in which the dissolved oxygen density in the electroless copper plating liquid is less than 4 ppm. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

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

  Basically, methods for producing a material having a conductive pattern made of a silver image on a support are roughly classified into a printing method, a photolithography method, a silver salt method, and other methods.

  The photolithography method is a subtractive method in which a photoresist is applied on a substrate having a uniform conductive metal layer, and after exposure and development, the conductive metal layer from which the resist has been peeled is removed by etching to obtain a conductive pattern. For example, in JP-A-5-16281, a resist containing an electroless plating catalyst is coated on a support, exposed and developed, and after removing the unexposed portion of the resist, electroless plating is performed. An additive method for obtaining a pattern is described in, for example, Japanese Patent Laid-Open No. 11-170421. However, in the photolithography method, a high-definition conductive pattern can be formed. However, since the manufacturing process is generally complicated, there is a problem that a large amount of material is lost in the process.

  As a printing method, for example, a method of screen-printing a conductive metal ink or conductive paste containing silver in a desired pattern is disclosed in, for example, JP-A-55-91199 (Patent Document 1), JP-A-2006-313891 ( Patent Document 2), Japanese Patent Application Laid-Open No. 2000-113147 (Patent Document 3), and the like. As a silver salt photographic method, a method using a silver salt diffusion transfer method is disclosed in, for example, International Publication No. 04/007810 pamphlet (Patent Document 4), and a method using directly developed silver (by chemical development processing), for example Japanese Patent Application Laid-Open No. 2004-221564 (Patent Document 5) describes, for example, Japanese Patent Application Laid-Open No. 2007-59270 (Patent Document 6) using a curing development method. As another method, a conductive image forming layer composed of a silver particle layer is formed by applying silver plating or the like on the transparent support, and the image forming layer is irradiated with high-density energy light to For example, Japanese Patent Application Laid-Open No. 10-151858 (Patent Document 7) describes a method of reducing the bonding force between the image forming layer and the support and obtaining a conductive pattern.

  The printing method, the silver salt photography method, and other methods are preferable from the viewpoint that the manufacturing process is not complicated compared to the photolithography method and the loss of materials used in the process is small.

  In recent years, high-definition wiring patterns are required and high conductivity is required, such as wiring substrates used in small devices such as mobile phones and digital cameras, and electromagnetic wave shielding films used in plasma displays. For such applications, as described in Patent Documents 3 to 5 described above, the conductivity can be further increased by metal plating (electroless plating and / or electrolytic plating) on the obtained silver image. Is useful. Also, in the case of an image where wiring is isolated like a printed circuit board, since electroplating is not possible, electroless plating is useful as a plating method.

  However, in the further downsizing of the apparatus as described above, when producing a wiring board having an extremely high-definition wiring pattern in which the interval between adjacent wirings is several tens of μm or less, it was obtained by the silver salt photography method and the printing method. When the electroless plating process is performed on the silver image, the adjacent wirings may be connected to each other due to the thick line width of the conductor circuit. In the use of an electromagnetic wave shielding film, if adjacent wirings are connected, transparency is impaired, and the screen becomes dark when used for a display. Further, in applications such as printed circuit boards and address electrodes, if they are connected to adjacent wirings, they cause malfunctions or short-circuits, which impairs commercial value.

  On the other hand, in the electroless copper plating bath, it is known that the dissolved oxygen concentration has a great influence on the precipitation of copper plating. When the dissolved oxygen concentration is high, the electroless copper plating bath is inactive, the plating rate is slow, and the copper plating is poor. In addition, when the dissolved oxygen concentration is low, it becomes an active bath and the plating speed increases, but adjacent wirings may be connected to each other, and it is unstable as a bath and eventually causes a decomposition reaction. Sometimes it ends up. For this reason, in electroless copper plating, it is known to perform air bubbling for supplying oxygen by blowing air into the plating bath in order to adjust and agitate the dissolved oxygen concentration in the plating bath. For example, JP-A-6-33254 (Patent Document 8) describes that the dissolved oxygen concentration is adjusted to a concentration suitable for the plating reaction by bubbling a gas in which the oxygen concentration is adjusted by mixing nitrogen gas. Japanese Patent Laid-Open No. 5-98455 (Patent Document 9) describes that the dissolved oxygen concentration is adjusted to a concentration suitable for the plating reaction by performing air bubbling using a specific apparatus.

  However, even when copper plating is performed using a plating bath in which the dissolved oxygen concentration is adjusted to a concentration suitable for the plating reaction, the wiring substrate has an extremely high-definition wiring pattern in which the interval between adjacent wirings is several tens of μm or less. When manufacturing the circuit board, there is a case where adjacent wirings are connected to each other due to a large line width of the conductor circuit. Moreover, when trying to improve the line width of the conductor circuit, there is a problem that high conductivity cannot be obtained.

For example, JP-A-10-190216 (Patent Document 10) is known as a plating method using an electroless copper plating bath divided into two stages. This method uses an alkali stripping type catalyst resist to apply a catalyst to a selected portion on a printed circuit board, and then strips the catalyst resist in the first electroless plating bath and thinly electroless copper plating on the catalyst applying portion. This is intended to prevent unnecessary catalyst and plating from adhering to the surface of the printed circuit board by performing thick electroless copper plating in the second electroless plating bath.
JP 55-91199 A JP 2006-313891 A JP 2000-113147 A International Publication No. 04/007810 Pamphlet JP 2004-221564 A JP 2007-59270 A JP-A-10-151858 JP-A-6-33254 JP-A-5-98455 JP-A-10-190216

  Accordingly, an object of the present invention is to simultaneously satisfy the conflicting problems of improving the line width of the conductor circuit and obtaining high conductivity. The line width of the conductor circuit by electroless copper plating is high. It is an object of the present invention to provide a method for manufacturing a conductive material that can form a wiring pattern with less thickness.

  The object of the present invention is to form a silver image on at least one surface on a support, and then plate the silver image in a first plating bath having a dissolved oxygen concentration of 4 ppm or more in an electroless copper plating solution. This can be solved by a method for producing a conductive material, characterized in that the treatment is performed, and then the plating treatment is performed in a second plating bath in which the dissolved oxygen concentration in the electroless copper plating solution is less than 4 ppm.

  ADVANTAGE OF THE INVENTION According to this invention, the electroconductive material which can form a wiring pattern with high electroconductivity and few line thickness of the conductor circuit by electroless copper plating can be provided.

  In the present invention, a silver image formed on a support is subjected to a plating treatment in a first plating bath in which the dissolved oxygen concentration in the electroless copper plating solution is 4 ppm or more, and then in the electroless copper plating solution. By conducting the plating process in the second plating bath having a dissolved oxygen concentration of less than 4 ppm, it is possible to form a conductor pattern with less line width. As described above, when the dissolved oxygen concentration in the plating bath is high, specifically, when the dissolved oxygen concentration in the electroless copper plating solution is 4 ppm or more, the electroless copper plating bath becomes inactive and the plating rate is slow. , Copper plating is not good. However, in such a first plating bath, the silver image edge is affected by the dissolved oxygen concentration from the two directions of the silver image side and the silver image surface, so that the amount of copper deposited on the silver image edge is the center of the silver image. Therefore, it is considered that the copper deposition is mainly concentrated in the central portion of the silver image, and the copper deposition at the edge of the silver image hardly occurs.

  On the other hand, when the dissolved oxygen concentration in the plating bath is low as described above, specifically, when the dissolved oxygen concentration in the electroless copper plating solution is less than 4 ppm, the bath becomes an active bath and the plating rate is increased. When electroless copper plating is performed on a silver image on a support in such an active bath, when producing a wiring board having an extremely high-definition wiring pattern in which the interval between adjacent wirings is several tens of μm or less Has a problem that the line width of the conductor circuit is increased. However, by performing an electroless copper plating treatment with the second plating bath on the image portion obtained by the treatment in the first plating bath, in the vicinity of the border line of the silver image edge where copper deposition hardly occurred, It is considered that copper can be deposited without increasing the line width, and more copper can be deposited in the central portion of the silver image. Therefore, after plating in the first plating bath with a high dissolved oxygen concentration, the plating treatment in the second plating bath with a low dissolved oxygen concentration is performed, so that the conductor has high conductivity and less line width. It is considered that a pattern can be formed.

  There are an electrolysis method and an electroless method for the plating treatment, and an electroless plating method is used as the plating treatment performed in the present invention. The electroless plating technique is described in “Electroless Plating” edited by Electroplating Research Society, Nikkan Kogyo Shimbun (1994). Electroless plating is so-called autocatalytic chemical reduction plating in which metal ions such as nickel and copper are reduced and deposited by a reducing agent, and this deposition reaction proceeds continuously to form a plating film. Although electroless plating using nickel-phosphorus or copper is widely used industrially today, the present invention uses electroless copper plating.

  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, trans-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.

  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, as a means for maintaining the dissolved oxygen concentration in the plating bath at 4 ppm or more in the first plating bath and less than 4 ppm in the second plating bath, the temperature of the plating solution or the plating solution is adjusted. In a management tank or the like often installed for the purpose, air bubbling is performed in the plating solution. The air used for air bubbling may be air or a gas in which the oxygen concentration is adjusted by mixing the nitrogen gas described in Patent Document 7 described above.

  The structure of the electroless copper plating tank used in the present invention will be described. The structure of the treatment bath used for the first plating bath and the second plating bath may be the same as long as it has a facility for maintaining the dissolved oxygen concentration in the plating bath, and is a commonly used known electroless copper. It may be equivalent to a plating tank. However, in the case of a plating treatment tank in which the plating bath is stirred only by air bubbling, the strength of stirring in the second plating bath tends to be insufficient, so equipment for stirring the plating bath by methods other than air bubbling is also provided. It is preferable to provide. Furthermore, it is more preferable if the first plating bath is equipped with equipment for stirring the plating bath by a method other than air bubbling.

  Air bubbling to the plating bath differs depending on the size of the bubbles to be generated and the composition of the electroless plating solution to be used. Usually, a dissolved oxygen concentration of 4 ppm or more is supplied by supplying more than 25 L per minute per 100 L. Can be maintained. Moreover, the dissolved oxygen concentration of less than 4 ppm can be maintained by supplying the amount of about 25 L or less per 100 L per minute. Air bubbling may be intermittent instead of continuous.

  In addition, the dissolved oxygen concentration in this invention can be measured using a dissolved oxygen concentration meter (made by DO meter Able company). If the dissolved oxygen concentration is excessive or insufficient, the amount of supplied oxygen may be changed by a method such as strengthening air bubbling.

  Further, the present invention provides a silver image pattern after a treatment with a first plating bath in which the dissolved oxygen concentration in the electroless copper plating solution is 4 ppm or more and a plating treatment with a second plating bath in which the dissolved oxygen concentration is less than 4 ppm. A plating treatment using a third, fourth or more number of plating baths may be performed. Here, the third and fourth plating baths use the same treatment tanks as those used for the first and second plating baths, and the dissolved oxygen concentration in the plating solution is 4 ppm or more, or 4 ppm. It may be a plating bath adjusted to less than that, and is not limited to electroless copper plating, but may be electrolytic plating. Further, a water washing step and a drying step may be provided between the plating treatments in the first and second plating baths.

  The upper limit value of the dissolved oxygen concentration in the plating solution of the first plating bath in the present invention is 5.7 ppm, and even at a dissolved oxygen concentration higher than this, even in the central portion of the silver image, a portion where no copper precipitation occurs is uniform. May not be obtained. On the other hand, the lower limit value of the dissolved oxygen concentration in the plating solution of the second plating bath is 2.0 ppm, and normal precipitates may not be obtained such as hump-like copper precipitates at a dissolved oxygen concentration below this, In addition, the plating bath may become unstable and a decomposition reaction may occur.

  In the present invention, examples of the method for forming a silver image on at least one surface of the support include a method for forming a silver image by a silver salt photographic method and a printing method. As a printing method, there is a method of printing a conductive metal ink containing silver or a conductive paste in a desired pattern, and examples of the printing method include a printing method using screen printing or an inkjet recording method. Examples of 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. In the present invention, an undercoat layer or an antistatic layer may be provided on the support as necessary.

  The conductive metal ink or conductive paste containing silver preferably contains silver mainly from the viewpoints of high conductivity, cost, productivity, ease of handling, and the like. Here, the main component means that 50% by mass or more of the total ultrafine metal particles contained in the conductive metal ink or conductive paste containing silver is silver, and more preferably 70% by mass or more. Examples of preferable metals other than silver include gold, copper, platinum, palladium, rhodium, ruthenium, iridium, osmium, nickel, and bismuth. In order to suppress migration specific to silver, gold, copper, Platinum and palladium are preferred. Examples of a method for containing a metal other than silver in a conductive metal ink or conductive paste containing silver include, for example, a method of containing palladium in silver ultrafine particles as disclosed in JP-A-2000-090737, As disclosed in JP 2001-35255 A, a method of mixing silver ultrafine particles and palladium ultrafine particles separately produced may be used. Examples of the conductive metal ink containing silver include a conductive metal ink containing copper such as a silver nanoparticle ink manufactured by Cima NanoTech. Further, the silver particles contained in the conductive metal ink or conductive paste are preferably 200 nm or less, more preferably 100 nm or less, and even more preferably 50 nm or less.

  The silver image formed on at least one surface of the support by screen printing or an ink jet recording method may then be increased in conductivity by, for example, high-temperature, long-time heat treatment, or described in Patent Document 2 described above. The conductivity may be increased by treatment with an acid.

  As described above, the present invention improves the increase in the line width of a conductor circuit that is recognized when a wiring board having an extremely high-definition wiring pattern in which the interval between adjacent wirings is several tens of μm or less is manufactured. Therefore, the present invention is more effective when trying to obtain a finer line pattern with higher definition. Specifically, it is extremely effective in a fine line pattern having a line width of 50 μm or less, more preferably 30 μm or less. However, when a high-definition fine line pattern is to be obtained by the printing method using the screen printing or the ink jet recording method, the lower limit of the line width of the fine line pattern is about 50 μm at present. On the other hand, according to the silver salt photography method described later, although it depends on the exposure method, a fine line pattern of about 10 μm is generally obtained. Therefore, the present invention is more effective for silver images obtained by the silver salt photographic system.

As a method of forming a silver image on at least one surface on a support by a silver salt photographic system, there are methods shown in the following (a), (b) or (c).
(A) A photosensitive material having at least a physical development nucleus layer and a silver halide emulsion layer is exposed on a support and subjected to development processing according to a silver salt diffusion transfer method, and then at least a silver halide emulsion layer which is no longer necessary is provided. How to wash with water.
(B) A method in which a photosensitive material having at least a silver halide emulsion layer is exposed on a support, subjected to a development treatment, and then subjected to a fixing treatment.
(C) A light-sensitive material having at least a silver halide emulsion layer on the support is exposed to light and subjected to a development treatment according to a hardening development method, and then at least the uncured silver halide emulsion layer which has become unnecessary is washed away with water. Method.

  The method (a) is a method according to the silver salt diffusion transfer method described in, for example, Japanese Patent Publication No. 42-23745, and the principle of the silver salt diffusion transfer method is disclosed in US Pat. No. 2,352,014. It is described in the book. That is, the exposed silver halide is developed, but the unexposed silver halide is dissolved in a soluble silver complex salt forming agent and transferred to the image receiving layer as a soluble silver complex salt. By depositing as silver, a positive silver image is formed.

  The method (b) is, for example, a method described in JP-A No. 2004-221564, and the exposed portion of the silver halide is reduced to a silver image by being developed (negative type). The silver halide in the exposed area is dissolved and removed by fixing. The method (c) is a curing development method described in, for example, JP-A-2007-59270. What is the curing development method? Photo. Sci. Magazine No. 11 p 1, A. G. By Tull (1963) or “The Theory of the Photographic Process (4th edition, p326-327)”, T. H. As described in James et al., An unhardened silver halide emulsion layer substantially free of hardener prepared on a support is developed with a developer containing a developing agent such as polyhydroxybenzene. By processing, when the exposed silver halide is reduced by the developing agent, the oxidized compound produced from the developing agent itself crosslinks the water-soluble polymer such as gelatin and hardens it into an image. There is a method for forming a relief image on a support.

  As the silver salt photographic system in the present invention, the silver image may be formed by any of the methods (a) to (c) described above, but the silver formed by the methods (b) and (c) above. Since the image is buried in gelatin, which is a binder, it is difficult to contact the plating solution, and the plating process may take time. Therefore, it is preferable that the silver image is plated on the silver image formed by the method (a), which is not covered with a very small amount of binder, or substantially covered with the binder.

  The method for forming a silver image on at least one surface of the support by the methods (a) to (c) will be described in detail below. (A) The silver image formation method using the method is abbreviated as type 1, (b) the silver image formation method using the method is abbreviated as type 2, and (c) the silver image formation method using the method is abbreviated as a type 3. Will be described in order.

<Type 1>
Type 1 light-sensitive material is exposed to a light-sensitive material having at least a physical development nucleus layer and a silver halide emulsion layer on the support in this order from the side closer to the support, and then halogenated in the image area which is an unexposed area. Silver particles are dissolved with a soluble silver complex salt forming agent and dissolved as a soluble silver complex salt, and the soluble silver complex salt diffused to the physical development nuclei is reduced with a reducing agent (developing agent) such as hydroquinone to precipitate metallic silver. Form an image. Thereafter, it is removed by washing with water, and the silver halide emulsion layer and the like are washed away to form a pattern with a silver image on the substrate.

  Further, the type 1 photosensitive material may further have a non-photosensitive layer as an outermost layer farthest from the support and / or an intermediate layer between the physical development nucleus layer and the silver halide emulsion layer. These non-photosensitive layers are layers 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 allows the developer to easily penetrate into the underlying silver halide emulsion layer and the physical development nucleus layer.

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

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

  As the physical development nuclei of the physical development nuclei layer possessed by the type 1 photosensitive material, fine particles (particle size of about 1 to several tens of nm) made of heavy metal or sulfide 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 fine particle layer of these physical development nuclei can be provided on the plastic resin film by vacuum deposition, cathode sputtering, or coating. From the viewpoint of production efficiency, a coating method is preferably used. The content of 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 may contain a hydrophilic binder. The amount of the hydrophilic binder is preferably about 10 to 500% by mass with respect to the physical development nucleus. As the hydrophilic binder, 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 binders are proteins such as gelatin, albumin and casein.

  Examples of the physical development nucleus layer 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, 2,3- Aldehyde equivalents such as dihydroxy-1,4-dioxane, compounds having active halogen such as 2,4-dichloro-6-hydroxy-s-triazine salt and 2,4-dihydroxy-6-chloro-triazine salt , Divinyl sulfone, divinyl ketone, N, N, N-triacryloyl hexahydrotriazine, compounds having two or more active three-membered ethyleneimino groups and epoxy groups in the molecule, and as a polymer hardener Contains one or more of various protein crosslinking agents (hardeners) such as dialdehyde starch It is preferable. Among these crosslinking agents, dialdehydes such as glyoxal, glutaraldehyde, 3-methylglutaraldehyde, succinaldehyde, and adipaldehyde are preferable, and glutaraldehyde is more preferable. The crosslinking agent preferably contains 0.1 to 30% by mass in the physical development nucleus layer, particularly 1 to 20% by mass, based on the total protein contained in the following base layer and physical development nucleus layer.

  In the type 1 light-sensitive material, it is preferable to have a base layer made of protein (protein-containing base layer; hereinafter simply referred to as a base layer) between the physical development nucleus layer and the transparent support. It is preferable to further have an easy adhesion layer such as vinylidene chloride or polyurethane between the transparent support and the base layer. As the protein used for the base layer, gelatin, albumin, casein or a mixture thereof is preferably used. The protein content in the base layer is preferably 10 to 300 mg per square meter.

  The physical development nucleus layer and the base layer can be applied by application methods such as dip coating, slide coating, curtain coating, bar coating, air knife coating, roll coating, gravure coating, and spray coating.

  In the type 1 photosensitive material, 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 preferable range for the halide composition of the silver halide emulsion used in the present invention, and it is preferable that the chloride content is 80 mol% or more, and it is particularly preferable that 90 mol% or more is chloride.

  In the production of silver halide emulsions, group VIII such as sulfites, lead salts, thallium salts, rhodium salts or complex salts thereof, iridium salts or complex salts thereof in the process of forming silver halide grains or physical ripening as necessary. A 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 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.

  Examples of the method for forming a silver image having an arbitrary pattern on at least one surface on a support using a type 1 photosensitive material 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 reticulated pattern original and the silver halide emulsion layer in close contact, or scanning exposure using various laser beams. There are ways to do this. 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.

  In the type 1 silver image forming method, a document having an arbitrary shape pattern such as a mesh pattern and the precursor are in close contact with each other and exposed, or a digital image of an arbitrary shape pattern is output with various laser light output devices. After scanning exposure to the precursor, physical development occurs by processing with a silver salt diffusion transfer developer, and the silver halide in the unexposed area is dissolved to form a silver complex salt, which is reduced on the physical development nucleus to form metallic silver. A silver thin film having a shape pattern can be obtained by precipitation. On the other hand, the exposed portion is chemically developed in the silver halide emulsion layer to become blackened silver. After development, the silver halide emulsion layer, intermediate layer and protective layer which are no longer needed are washed away with water, and a silver thin film having a shape pattern is exposed on the surface.

  As a method for removing a layer provided on a physical development nucleus layer such as a silver halide emulsion layer after development, there is a method of removing by washing with water or transferring to a release paper. 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 solution (silver complex diffusion transfer developer) on the silver halide emulsion layer in advance with a roller or the like, and remove the silver halide emulsion layer and the release paper. In this method, the silver halide emulsion layer and the like are transferred from a plastic resin film to a release paper and peeled off. As the release paper, water-absorbing paper or 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 developing solution for silver salt diffusion transfer development will be described. The developer is an alkaline solution containing a soluble silver complex salt forming agent and a reducing agent. 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 for reducing the soluble silver complex salt to deposit metallic silver on the physical development nucleus. .

  Soluble silver complex forming agents used in the developer include thiosulfates such as sodium thiosulfate and ammonium thiosulfate, thiocyanates such as sodium thiocyanate and ammonium thiocyanate, and sulfites such as sodium sulfite and potassium bisulfite. 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, alkylsulfones, and others described in the specification, “The Theory of the Photographic Process (4th edition, p474-475)”, T. et al. H. Examples include compounds described in James.

  Among these soluble silver complex salt forming agents, alkanolamine is particularly preferable. A relatively low value is obtained for the surface resistance of the transparent conductive material developed with a processing solution containing an alkanolamine.

  Examples of the alkanolamine include N- (2-aminoethyl) ethanolamine, diethanolamine, N-methylethanolamine, triethanolamine, N-ethyldiethanolamine, diisopropanolamine, ethanolamine, 4-aminobutanol, N, N- Examples include dimethylethanolamine, 3-aminopropanol, N-ethyl-2,2′-iminodiethanol, 2-methylaminoethanol, 2-amino-2-methyl-1-propanol and the like.

  These soluble silver complex salt forming agents can be used alone or in combination.

  The reducing agent used in the developer is a development known in the field of photographic development as described in Research Disclosure Item 17643 (December 1978) and 18716 (November 1979), 308119 (December 1989). The main drug 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. These reducing agents can be used alone or in combination.

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

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

  In the present invention, prior to the plating treatment of the silver image pattern obtained by any of the photographic production methods (a) to (c), a known degreasing treatment as shown below may be performed.

  The degreasing process is a process for washing and removing oil and the like adhering to the substrate, and known processing conditions can be used. In general, an alkaline degreasing agent, a surfactant, an organic solvent, or the like is used, and immersion treatment is performed at 10 to 60 ° C. for 1 to 10 minutes.

<Type 2>
This is a method of performing direct development processing. For example, when using a negative emulsion, a silver halide grain of an optical sensor is exposed imagewise to form a latent image, and the latent image is used as a catalyst to reduce the silver halide with a reducing agent such as hydroquinone in the developer. Form silver. Thereafter, the unexposed silver halide is removed by a fixing process, and a pattern of silver particles held in an image-like binder is formed on the substrate.

  Type 2 photosensitive material is provided with a silver halide emulsion layer on the support as an optical sensor. The halogen element contained in the silver halide of the silver halide emulsion layer is any of chlorine, bromine, iodine and fluorine. There may be a combination thereof. For the formation of silver halide emulsion grains, methods such as forward mixing, reverse mixing, and simultaneous mixing are used. Of these, the use of the controlled double jet method is preferred from the viewpoint of obtaining silver halide emulsion grains having a uniform grain size. 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 silver halide grains is not particularly limited. For example, the shape can be various shapes such as a spherical shape, a cubic shape, a flat plate shape (hexagon flat plate shape, a triangular flat plate shape, a quadrangular flat plate shape, etc.), an octahedron shape, and a tetrahedron shape. Can be.

  In the production of silver halide emulsions, group VIII such as sulfites, lead salts, thallium salts, rhodium salts or complex salts thereof, iridium salts or complex salts thereof in the process of forming silver halide grains or physical ripening as necessary. A 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 silver halide emulsion layer contains a binder. As the binder, both a water-insoluble polymer and a water-soluble polymer can be used as the binder, but it is preferable to use a water-soluble polymer. Preferred water-soluble polymers include, for example, gelatin, polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), starch and other polysaccharides, cellulose and derivatives thereof, polyethylene oxide, polyvinyl amine, chitosan, polylysine, polyacrylic acid, poly Examples include alginic acid, polyhyaluronic acid, and carboxycellulose.

  In addition to the above water-soluble polymer, a polymer latex as a water-insoluble polymer can also be used for the silver halide emulsion layer. 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 copolymers, styrene / butadiene copolymers, and styrene.・ P-methoxystyrene copolymer, styrene / vinyl acetate copolymer, vinyl acetate / vinyl chloride copolymer, vinyl acetate / diethyl maleate copolymer, methyl methacrylate / acrylonitrile copolymer, methyl methacrylate / butadiene copolymer Polymer, methyl methacrylate / styrene copolymer, methyl methacrylate / vinyl acetate copolymer, methyl methacrylate / vinylidene chloride copolymer, methyl acrylate / acrylonitrile copolymer, methyl acrylate / butadiene copolymer Methyl acrylate-styrene copolymer, methyl acrylate-vinyl acetate copolymer, an acrylic acid-butyl acrylate copolymer, methyl acrylate-vinyl chloride copolymer, and butyl acrylate-styrene copolymer. The average particle size of the polymer latex used in the silver halide emulsion layer is preferably 0.01 to 1.0 [mu] m, more preferably 0.05 to 0.8 [mu] m.

  The polymer latex is preferably used at a mass ratio (polymer latex / water-soluble polymer) of 1.0 or less because the polymer latex has an adverse effect on coating properties when used in an excessive amount. In addition, regarding the total amount of polymer latex and water-soluble polymer contained in the silver halide emulsion layer, that is, the total amount of binder, if the amount of the binder is small, the coating property is adversely affected, and stable silver halide grains are also obtained. On the other hand, if the amount is too large, the electroconductivity cannot be obtained unless a large amount of plating is performed, and the productivity is greatly affected. The mass ratio (silver / total binder) of the preferred silver halide (in terms of silver) and the total binder is 1.2 or more, more preferably 1.5 to 3.5.

  The silver halide emulsion layer of the type 2 photosensitive material is preferably hardened with a hardener. Examples of the hardener include inorganic compounds such as chrome alum, aldehydes such as formaldehyde, glyoxal, malealdehyde, and glutaraldehyde, N-methylol compounds such as urea and ethyleneurea, mucochloric acid, and 2,3-dihydroxy-1 Aldehyde equivalents such as 1,4-dioxane, 2,4-dichloro-6-hydroxy-s-triazine salts and compounds having active halogen such as 2,4-dihydroxy-6-chloro-triazine salts, divinyl sulfone , Divinyl ketone, N, N, N-triacryloyl hexahydrotriazine, compounds having two or more active three-membered ethyleneimino groups or epoxy groups in the molecule, dialdehyde starch as a polymer hardener Etc. and other Research Disclosure Items 17643 (December 1978) and 18716 (November 1979), 308119 (December 1989) can be used. The hardeners can be used alone or in combination. The hardener is preferably contained in an amount of 0.1 to 10% by weight, particularly 0.5 to 8% by weight, based on the binder contained in the silver halide emulsion layer.

  For the silver halide emulsion layer, known photographic additives similar to the type 1 light-sensitive material can be used for various purposes.

  In the type 2 light-sensitive material, a backing layer or an overlayer on the silver halide emulsion layer can be provided on the opposite side of the support from the silver halide emulsion layer, if necessary. Further, a non-sensitizing dye or pigment having an absorption maximum in the photosensitive wavelength region of the silver halide emulsion layer can be contained by the same purpose and method as described in Type 1.

  As a method for forming a silver image having an arbitrary pattern on at least one surface of the support by the type 2 method, exposure can be performed by the same method as in type 1.

  After the type 2 photosensitive material is exposed, at least development processing, fixing processing, and water washing processing are performed.

  The developer used for forming a silver image by the type 2 method comprises a developing agent, a preservative, an alkali agent, and an antifoggant as a basic composition. Specific examples of the developing agent include hydroquinone, ascorbic acid, p-aminophenol, p-phenylenediamine, phenidone and the like. Some of these may be contained in the photosensitive material. Examples of preservatives include sulfite ions. The alkaline agent is necessary for exhibiting the reducing ability of the developing agent, and is added so that the pH of the developer is 9 or more, preferably 10 or more. In addition, a buffering agent such as carbonate or phosphate is also used in order to keep the basicity stably. Furthermore, examples of the antifoggant added so that silver halide grains having no development nucleus are not reduced include bromide ions, benzimidazole, benzotriazole, 1-phenyl-5-mercaptotetrazole and the like.

  Furthermore, a soluble silver complex salt forming agent can be contained in the developer. Specific examples of soluble silver complex forming agents 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. Thioethers such as 1,10-dithia-18-crown-6, 2,2′-thiodiethanol, oxadolidones, 2-mercaptobenzoic acid and its derivatives, cyclic imides such as uracil, alkanolamines, diamines, JP-A-9-171257 discloses mesoionic compounds, 5,5-dialkylhydantoins, alkylsulfones, and other “The Theory of the Photographic Process (4th edition, p474-475)”, T. et al. H. Examples include compounds described in James.

  Of these soluble silver complex salt forming agents, alkanolamines are particularly preferred. Examples of the alkanolamine include N- (2-aminoethyl) ethanolamine, diethanolamine, N-methylethanolamine, triethanolamine, N-ethyldiethanolamine, diisopropanolamine, ethanolamine, 4-aminobutanol, N, N- Examples include dimethylethanolamine, 3-aminopropanol, and 2-amino-2-methyl-1-propanol.

  These soluble silver complex salt forming agents can be used alone or in combination. The amount of the soluble silver complex salt forming agent used is 0.1 to 40 g / L, preferably 1 to 20 g / L. The development processing temperature is usually selected between 15 ° C and 45 ° C, more preferably 25-40 ° C.

  In the type 2 method, the fixing treatment is performed for the purpose of removing and stabilizing the silver salt in the undeveloped portion. The fixing process can be performed by using a fixing process technique used in known silver salt photographic film, photographic paper, film for printing plate making, emulsion mask for photomask, etc. A fixing solution described in p321.

  Among them, a fixing solution containing a desilvering agent other than thiosulfate is preferable. In this case, as a desilvering agent, thiocyanates such as sodium thiocyanate and ammonium thiocyanate, sulfites such as sodium sulfite and potassium bisulfite, 1,10-dithia-18-crown-6, 2,2 ′ -Thioethers such as thiodiethanol, oxadoridones, 2-mercaptobenzoic acid and derivatives thereof, cyclic imides such as uracil, alkanolamines, diamines, mesoionic compounds described in JP-A-9-171257, 5,5 -Dialkylhydantoins, alkylsulfones, and others "The Theory of the Photographic Process (4th edition, p474-475)", T. et al. H. Examples include compounds described in James.

  Among these desilvering agents, alkanolamine is particularly preferable. Alkanolamine has the same meaning as the soluble silver complex forming agent described in the diffusion transfer developer. Further, thiocyanate has a high desilvering ability, but it is not preferable to use it from the viewpoint of safety to the human body.

  These desilvering agents can be used alone or in combination. The amount of the desilvering agent used is preferably 0.01 to 5 mol, more preferably 0.1 to 3 mol per liter of the fixing solution in total of the desilvering agent.

  In addition to the desilvering agent, the fixing solution may contain sulfite or bisulfite as a preservative, and acetic acid, borate amine, phosphate, or the like as a pH buffer. In addition, water-soluble aluminum (eg, aluminum sulfate, aluminum chloride, potassium alum) as a hardener, dibasic acid (eg, tartaric acid, potassium tartrate, sodium tartrate, sodium citrate, lithium citrate, Potassium citrate and the like) can also be included. The preferred pH of the fixing solution varies depending on the type of desilvering agent, and is 8 or more, preferably 9 or more, particularly when an amine is used. The fixing processing temperature is usually selected between 10 ° C. and 45 ° C., more preferably 18-30 ° C.

<Type 3>
This is a method using a curing development method. In this method, a silver halide grain of an optical sensor is exposed imagewise to form a latent image, and when this is used as a catalyst to reduce silver halide, its oxidized form such as hydroquinone is a reducing agent that has gelatin hardening action. An agent is used to form metallic silver, and at the same time, gelatin around the metallic silver is hardened to form an image, and then washed away with water to wash away non-hardened portions. Similar to Type 2, silver particles are held in the binder, but only the base material remains in the non-image area.

  In the type 3 photosensitive material, a silver halide emulsion layer is provided on a support as an optical sensor. As the silver halide contained in the type 3 photosensitive material, the same silver halide as that used in the type 2 photosensitive material can be used.

  The silver halide emulsion layer possessed by the type 3 photosensitive material contains a binder. In the present invention, both the water-insoluble polymer and the water-soluble polymer can be used as a binder, but it is preferable to use a water-soluble polymer. Preferred binders in the present invention include, for example, proteins such as gelatin and casein, polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), polysaccharides such as starch, cellulose and derivatives thereof, polyethylene oxide, polyvinylamine, chitosan, polylysine. , Polyacrylic acid, alginic acid, hyaluronic acid, carboxycellulose and the like. Of these water-soluble polymers, proteins such as gelatin are preferred.

  In addition to the water-soluble polymer, a polymer latex as a water-insoluble polymer can be used for the silver halide emulsion layer of the type 3 photosensitive material. 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 copolymers, styrene / butadiene copolymers, and styrene.・ P-methoxystyrene copolymer, styrene / vinyl acetate copolymer, vinyl acetate / vinyl chloride copolymer, vinyl acetate / diethyl maleate copolymer, methyl methacrylate / acrylonitrile copolymer, methyl methacrylate / butadiene copolymer Polymer, methyl methacrylate / styrene copolymer, methyl methacrylate / vinyl acetate copolymer, methyl methacrylate / vinylidene chloride copolymer, methyl acrylate / acrylonitrile copolymer, methyl acrylate / butadiene copolymer Methyl acrylate-styrene copolymer, methyl acrylate-vinyl acetate copolymer, an acrylic acid-butyl acrylate copolymer, methyl acrylate-vinyl chloride copolymer, and butyl acrylate-styrene copolymer. 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.

Regarding the total amount of water-soluble polymer and polymer latex contained in the silver halide emulsion layer of the type 3 photosensitive material, that is, the total binder amount, if the amount of the binder is small, the coating property is adversely affected, and stable silver halide. On the other hand, particles cannot be obtained. On the other hand, if the amount is too large, it becomes difficult to obtain electrical conductivity, and the productivity is greatly affected. The mass ratio (silver / total binder) between the preferred silver halide (in terms of silver) and the total binder is 0.5 or more, more preferably 1.5 to 3.5. Moreover, a preferable total binder amount is 0.05-3 g / m < ² >, More preferably, it is 0.1-1 g / m < ² >.

  For the type 3 photosensitive material, similar to the type 2 photosensitive material, known photographic additives can be used for various purposes.

  For Type 3 photosensitive materials, if necessary, a backing layer on the side opposite to the silver halide emulsion layer of the support, an overlayer on the silver halide emulsion layer, an undercoat layer under the silver halide emulsion layer, etc. Can be provided. Similarly to the type 1 and type 2 photosensitive materials, a non-sensitizing dye or pigment having an absorption maximum in the photosensitive wavelength region of the silver halide emulsion layer can be contained.

For the over layer and the undercoat layer of the type 3 photosensitive material, the same binder as that for the silver halide emulsion layer can be used. The preferred binder amount varies depending on the purpose of use of each layer. In particular, when the layers are cured in an image form using a curing development process and it is desired to leave only necessary portions, for example, an electroless plating is applied to the over layer. In the case of containing catalyst nuclei, etc., since the curing reaction occurring in the silver halide emulsion layer is utilized, it is preferably as thin as possible, and the preferred amount is 0.1 g / m ² or less, more preferably 0.05-0. 001 g / m ² . Further, the over layer and the undercoat layer may contain known surfactants, development inhibitors, irradiation preventing dyes, pigments, matting agents, lubricants and the like.

  It is particularly preferable that the type 3 photosensitive material contains a hardened developer. Curing developers include polyhydroxybenzenes such as hydroquinone, catechol, chlorohydroquinone, pyrogallol, bromohydroquinone, isopropylhydroquinone, toluhydroquinone, methylhydroquinone, 2,3-dichlorohydroquinone, 2,3-dimethylhydroquinone, 2,3- Dibromohydroquinone, 2,5-dihydroxy-1-acetophenone, 2,5-dimethylhydroquinone, 4-phenylcatechol, 4-t-butylcatechol, 4-s-butylpyrogalol, 4,5-dibromocatechol, 2,5- Diethylhydroquinone, 2,5-benzoylaminohydroquinone, and the like. Aminophenol compounds such as N-methyl-p-aminophenol, p-aminophenol-2,4-diaminophenol, p-benzylaminophenol, 2-methyl-p-aminophenol, 2-hydroxymethyl-p- Aminophenol and the like, and other known curing developers described in JP 2001-215711 A, JP 2001-215732 A, JP 2001-312031 A, and JP 2002-62664 A, for example, are used. In particular, benzene having a hydroxyl group substituted at least in the 1,2-position or 1,4-position of the benzene nucleus is preferred. Further, these curable developers can be used in combination. Further, 3-pyrazolidones such as 1-phenyl-3-pyrazolidone, 1-p-tolyl-3-pyrazolidone, 1-phenyl-4-methyl-3-pyrazolidone, 1-phenyl-4,4-dimethyl-3- It is also possible to use reducing agents used in known photographic developers such as pyrazolidone and 1-p-chlorophenyl-3-pyrazolidone in combination with the above-described cured developer.

  These hardened developers may be contained in any layer of the conductive material precursor, but are preferably contained in the silver halide emulsion layer or the undercoat layer, and particularly in the silver halide emulsion layer. preferable. A preferable amount to be contained is an amount sufficient to make the water-soluble binder of the silver halide emulsion layer water-resistant, and thus varies depending on the amount of the water-soluble binder used. A preferable amount of the hardened developer is 0.01 to 0.5 mmol / water-soluble binder 1 g, more preferably 0.1 to 0.4 mmol / water-soluble binder 1 g. These hardened developers may be dissolved in the coating solution or contained in each layer, or may be dissolved in an oil dispersion and contained in each layer.

The type 3 photosensitive material preferably contains a swelling inhibitor. The swelling inhibitor in the present invention is used to prevent blurring of the image by preventing the water-soluble binder from swelling when the photosensitive material is processed with a curing developer, and to increase conductivity. Whether or not it acts as a swelling inhibitor was examined by adding gelatin to a 5% aqueous gelatin solution at pH 3.5 so that the swelling inhibitor would be 0.35 mol / L, and in this test gelatin precipitation occurred. All the chemicals that cause the occurrence of swelling act as swelling inhibitors. Specific examples of the swelling inhibitor include inorganic salts such as sodium sulfate, lithium sulfate, calcium sulfate, magnesium sulfate, sodium nitrate, calcium nitrate, magnesium nitrate, zinc nitrate, magnesium chloride, sodium chloride, manganese chloride, and magnesium phosphate, Or, for example, benzenesulfonic acid, diphenylsulfonic acid, 5-sulfosalicylic acid, p-toluenesulfonic acid, phenol disulfonic acid, α-naphthalenesulfonic acid, β-naphthalenesulfonic acid, 1,5-naphthalenesulfonic acid, 1-hydroxy-3 Sulfonic acids such as 1,6-naphthalenedisulfonic acid and dinaphthylmethanesulfonic acid, such as polyvinylbenzenesulfonic acid, a copolymer of maleic anhydride and vinylsulfonic acid, and a polymer precipitant such as polyvinylacrylamide Examples include compounds used. These swelling inhibitors may be used alone or in combination, but it is preferable to use inorganic salts, particularly sulfates. These swelling inhibitors may be contained in any layer of the light-sensitive material, but are particularly preferably contained in the silver halide emulsion layer. The preferred content of these swelling inhibitors 0.01 to 10 g / m ^2, still more preferably 0.1-2 g / m ^2.

  Examples of a method for forming a silver image having an arbitrary pattern on at least one surface on a support by the method of type 3 include formation of a silver thin film having a mesh pattern. The exposure can be performed by the method described in type 2.

  As a development processing method for forming a silver image having an arbitrary pattern on the support by the type 3 method, the type 3 photosensitive material is exposed and then cured and developed. Cured developers include alkaline substances such as potassium hydroxide, sodium hydroxide, lithium hydroxide, tribasic sodium phosphate, or amine compounds, thickeners such as carboxymethyl cellulose, development aids such as 3-pyrazolidinones, and antifogging. Agents such as potassium bromide, development modifiers such as polyoxyalkylene compounds, silver halide solvents such as thiosulfate, thiocyanate, cyclic imide, thiosalicylic acid, mesoionic compounds and the like. it can. The pH of the developer is usually 10-14. Preservatives used in ordinary silver salt photographic developers, such as sodium sulfite, have the effect of stopping the curing reaction due to curable development, so in the cured developers in the present invention, the preservative is used in an amount of at least 20 g / L or less, The amount used is preferably 10 g / L or less.

  The cured developer contains a hardened developer when the photosensitive material does not contain a hardened developer. As the hardened developer, the same hardened developer as that contained in the photosensitive material can be used. A preferable content of the hardened developer is 1 to 50 g / L. When the hardened developer is contained in the developer, the preservability is poor and the air is immediately oxidized. Therefore, it is preferable to dissolve in an alkaline aqueous solution immediately before use.

  The type 3 curable developer preferably contains a swelling inhibitor. As the swelling inhibitor, the same swelling inhibitor as that contained in the photosensitive material can be used. The content of a preferred swelling inhibitor is 50 to 300 g / L, preferably 100 to 250 g / L.

  The method for performing the type 3 curing and developing treatment may be an immersion method or a coating method. In the immersion method, for example, the photosensitive material is transported while being immersed in a processing solution stored in a large amount in a tank, and in the coating method, for example, about 40 to 120 ml of processing solution is applied on the photosensitive material per square meter. To do. In particular, when a curable developer containing a curable developer is used, it is preferable to use a coating method and not to repeatedly use the curable developer.

  The type 3 curing and developing treatment conditions are as follows. The development temperature is 2 to 30 ° C, and 10 to 25 ° C is more preferable. The development time is 5 to 30 seconds, preferably 5 to 10 seconds.

  In the development processing method for forming a silver image having an arbitrary pattern on the support by the method of type 3, the step of removing the silver halide emulsion layer in the non-image part and exposing the support surface after curing development Is included. Since the main purpose of this step is to remove the silver halide emulsion, the processing solution used in this step contains water as the main component. The treatment liquid may contain a buffer component. Moreover, a preservative can be contained in order to prevent the removed gelatin from being spoiled. As a method of removing the silver halide emulsion, there are a method of rubbing with a sponge or the like, a method of peeling off by applying a roller to the film surface and slipping, a method of winding the roller by contacting the roller with the film surface, and the like. As a method of applying the treatment liquid stream to the silver halide emulsion surface, a shower method, a slit method, or the like can be used alone or in combination. Also, a plurality of showers and slits can be provided to increase the removal efficiency.

  Create a relief image by removing the non-image area silver halide emulsion layer in the type 3 method and then processing with a solution containing a hardener well known to those skilled in the art. I can do it. Various hardeners such as chrome alum, aldehydes such as formaldehyde, ketones such as diacetyl, mucochloric acid, and the like can be used.

  In Type 3, the photosensitive material can be processed with a physical developer containing a silver halide solvent after the curing and developing process to increase the silver in the relief image cured by the curing and developing to obtain conductivity. The physical development process may be before or after the removal process of the silver halide emulsion layer, but since the silver halide in the non-image area can also be used as a silver supply source, the physical development process is performed before the removal. Preferably it is done. Further, silver can be further increased in the physical development step by supplying further silver ions, such as adding a silver salt to the physical developer.

  As the reducing agent used in the physical developer, a developing agent known in the field of photographic development can be used. For example, polyhydroxybenzenes such as hydroquinone, catechol, pyrogallol, methylhydroquinone, chlorohydroquinone, 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. These reducing agents can be used alone or in combination.

  The pH of the physical developer is preferably 8 or more, more preferably 9-11. In order to adjust to a desired pH, an alkali agent such as sodium hydroxide or potassium hydroxide, or a buffering agent such as phosphoric acid or carbonic acid is contained alone or in combination. The physical developer of the present invention preferably contains a preservative such as sodium sulfite or potassium sulfite.

It is preferable to add bromides such as potassium bromide and sodium bromide to the physical developer. This is because when the development is performed in the presence of an appropriate amount of bromide, the conductivity of the obtained metallic silver is improved. A preferable bromide concentration is 1 × 10 ⁻⁴ mol / L or more and 1 × 10 ⁻² mol / L or less.

  The potassium ion concentration of the physical developer is preferably 70 mol% or more of the total alkali metal ions in the physical developer. This is because the conductivity of the obtained metallic silver is relatively good even when the precursor is physically developed to some extent by setting the potassium ion concentration to 70 mol% or more. Potassium ions may be supplied in any form and method. For example, a method in which a hydroxide salt, a sulfite, a carbonate, a carboxylate, or the like is previously added to a physical developer can be used.

  The physical developer contains a soluble silver complex salt forming agent. A soluble silver complex salt forming agent is a compound that dissolves a non-photosensitive silver salt to form a soluble silver complex salt. Soluble silver complex forming agents used in physical developers include thiosulfates such as sodium thiosulfate and ammonium thiosulfate, thiocyanates such as sodium thiocyanate and ammonium thiocyanate, sodium sulfite and potassium bisulfite. Sulfites, 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, alkylsulfones, and the like as described in the specification of the specification, “The Theory of the Photographic Process (4th edition, p474-475)”, T. et al. H. Examples include compounds described in James.

  Among these soluble silver complex salt forming agents, alkanolamine is particularly preferable. A relatively low value is obtained for the surface resistance of the transparent conductive material developed with a processing solution containing an alkanolamine.

  Examples of the alkanolamine include N- (2-aminoethyl) ethanolamine, diethanolamine, N-methylethanolamine, triethanolamine, N-ethyldiethanolamine, diisopropanolamine, ethanolamine, 4-aminobutanol, N, N- Examples include dimethylethanolamine, 3-aminopropanol, and 2-amino-2-methyl-1-propanol.

  These soluble silver complex salt forming agents can be used alone or in combination. The content of the soluble silver complex salt forming agent is preferably 0.001 to 5 mol, more preferably 0.005 to 1 mol, per liter of the processing solution. The content of the reducing agent is preferably from 0.01 to 1 mol, more preferably from 0.05 to 1 mol, per liter of the treatment liquid.

The physical developer may further contain silver ions. The preferable content of silver ions is 0.01 to 1 mol / L, more preferably 0.02 to 0.5 mol / L. Alternatively, a silver halide emulsion having low sensitivity may be contained in the light-sensitive material instead of containing silver ions in the physical developer. The low-sensitivity silver halide emulsion means a silver halide emulsion having a sensitivity of 70% or less of a silver halide emulsion (hereinafter abbreviated as a high-sensitivity emulsion) used as a light sensor in a photosensitive material. The low-sensitivity silver halide emulsion (hereinafter abbreviated as low-sensitivity emulsion) is preferably contained in a light-sensitive material in an amount of 0.5 to 5 g / m ² , more preferably 1 to 3 g / m ² in terms of silver. The ratio of the high-sensitivity silver emulsion to the low-sensitivity emulsion is not particularly limited, but a preferable range is converted into silver, and a high-sensitivity emulsion: low-sensitivity emulsion = 1: 10 to 2: 1, more preferably 1: 5. 1: 1.

  The method for performing the physical development treatment using the physical developer may be an immersion method or a coating method. In the immersion method, for example, the photosensitive material is transported while being immersed in a processing solution stored in a large amount in a tank, and in the coating method, for example, about 40 to 120 ml of processing solution is applied on the photosensitive material per square meter. To do.

  Preferred physical development processing conditions for improving the conductivity and metallic luster are as follows. The development temperature is 2 to 25 ° C, and 10 to 20 ° C is more preferable. The development time is 30 to 180 seconds, preferably 40 to 120 seconds.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the examples.

<Preparation of conductive paste>
An aqueous solution in which 3.5 g of dextrin is dissolved in 31.5 g of ion-exchanged water and an aqueous solution in which 8.5 g of silver nitrate is dissolved in 41.5 g of ion-exchanged water are mixed. The solution was slowly added dropwise over a period of minutes. After 1 hour, stirring was stopped and left for 12 hours. Thereafter, decantation was performed, 25 g of ion-exchanged water was added to 25 g of the obtained precipitate, redispersion was performed, and centrifugation was performed to obtain a solid precipitate. 7 g of ion-exchanged water was added to the solid precipitate to obtain a conductive paste having a solid content of 38% by mass and a specific gravity of 1.4.

  Concentrated nitric acid was added to a part of the obtained conductive paste to form silver nitrate, and titration was performed using an aqueous potassium iodide solution to determine the silver concentration. The obtained silver concentration is 32% by mass, and 6% by mass corresponding to the difference from the solid content of 38% by mass corresponds to the content of a dispersant other than silver. As a result of observation with an electron microscope, the particle size of the silver particles was about 20 nm.

  The conductive paste is line-and-lined to a line thickness of 3.0 μm, a line width of 50.0 μm, and a pitch of 300 μm by screen printing on a 100 μm-thick polyethylene terephthalate film (manufactured by Teijin DuPont Films) that has been subjected to easy adhesion treatment A space image was printed to obtain a silver image pattern.

  The silver image pattern was degreased and then electroless copper plated. The degreasing treatment was carried out at a temperature of 60 ° C. for 1 minute by using a Meltex Co., Ltd. product and a cleaner 160 of 50 g / L. For electroless copper plating, a thin electroless copper plating made by Meltex, Melplate CU-5100 is constructed with a standard dilution, and the dissolved oxygen concentration is adjusted to 5.0 ppm. After performing the plating process for 5 minutes, the conductive material A was produced by immediately performing the plating process at 50 ° C. for 10 minutes in the second plating bath in which the dissolved oxygen concentration was adjusted to 3.0 ppm. In the first plating bath, by using a commercially available air pump, plating is performed by air bubbling at 50 L / min with respect to 100 L of plating solution and at 15 L / min with respect to 100 L of plating solution in the second plating solution. The dissolved oxygen concentration in the liquid was adjusted.

  When the fine line pattern of the conductive material A was observed at a magnification of 2100 using an optical microscope, 49.8 μm of electroless copper was deposited on a 50.0 μm silver image fine line. It was 0.14 ohm / square when the surface resistance value of the obtained line and space image was measured using the low resistivity meter (the Mitsubishi Chemical Corporation make, Loresta GP). The light transmittance of the conductive material A was 45.3% as a result of measuring the total light transmittance of the line and space image portion with a double beam type haze computer manufactured by Suga Test Instruments Co., Ltd.

<Comparative Example 1>
A comparative conductive material B was prepared in the same manner as in Example 1 except that the dissolved oxygen concentration in the first plating bath was adjusted to 3.0 ppm in the electroless copper plating of Example 1 above. When the thin line pattern of the conductive material B was observed at a magnification of 2100 using an optical microscope, 56.2 μm of electroless copper was deposited on a 50.0 μm silver image thin line. It was 0.11 ohm / square when the surface resistance value of the obtained line and space image was measured using the low resistivity meter (the Mitsubishi Chemical Corporation make, Loresta GP). The light transmittance of the conductive material B was 40.8% as a result of measuring the total light transmittance of the line and space image portion with a double beam type haze computer manufactured by Suga Test Instruments Co., Ltd.

A light-sensitive material used in the silver salt photographic system (a), which is a method according to the silver salt diffusion transfer method, was prepared as follows. After applying an adhesive layer of 50 mg / m ² of gelatin to a polyethylene terephthalate film having a subbing layer containing vinylidene chloride having a thickness of 100 μm, the physical development nucleus layer containing the following palladium sulfide sol was added to the solid content of palladium sulfide. Was applied to 0.4 mg / m ² and dried.

<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 physical development nucleus layer coating solution>
50 ml of palladium sulfide sol
20% 1% gelatin solution
Surfactant (S-1) 0.2g
Add water to make a total volume of 2000 ml.

  Subsequently, a backing layer having the following composition was applied on the side opposite to the side on which the physical development nucleus layer was applied.

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

  Subsequently, a silver halide emulsion layer and a non-photosensitive layer coating solution having the following composition were prepared. The silver halide emulsion was prepared by a general double jet mixing method for photographic silver halide emulsions. A silver halide emulsion layer was coated on the physical development nucleus layer. This silver halide emulsion was prepared with 95 mol% of silver chloride and 5 mol% of silver bromide and an average grain size of 0.1 μm. To this silver halide emulsion, sodium thiosulfate and chloroauric acid were added and chemically sensitized at 50 ° C. The silver halide emulsion has a silver (silver nitrate) / gelatin mass ratio of 2.0.

Using the silver halide emulsion thus prepared, the following silver halide emulsion layer coating solution was prepared. At the same time, the following non-photosensitive layer coating solution was prepared, and the non-photosensitive layer coating solution and the silver halide emulsion layer coating solution were simultaneously slide-coated on the physical development nucleus layer in this order. The obtained photosensitive material had a total amount of 3.0 g including 3.0 g of silver per 1 m ² (silver nitrate) and 1.0 g of gelatin including the non-photosensitive layer.

<Silver halide emulsion layer coating solution>
50g gelatin
Silver halide emulsion 300 g Silver nitrate equivalent 1-phenyl-5-mercaptotetrazole 0.3 g
Surfactant (S-1) 3g

<Non-photosensitive layer coating solution>
100g gelatin
Amorphous silica matting agent (average particle size 3.5μm) 1g
Surfactant (S-1) 1g
Surfactant (S-2) 10mg

The light-sensitive material thus obtained was placed in a close contact printer using a mercury lamp as a light source, and a wiring pattern (1 × 5 cm electrodes were arranged so that the distance between the two electrodes was 10 cm, between which the fine line width was 6.3 μm and the fine line was A positive document on which 1536 fine lines with a spacing of 6.3 μm are drawn is brought into close contact, and exposed with an energy amount of 0.6 mJ / cm ² , followed by the following developer-1 (development for photographic process (a)) The film was immersed in the liquid for 40 seconds at 25 ° C. and then washed with warm water to obtain a silver image pattern on which a silver wiring pattern was formed.

<Developer-1>
Sodium hydroxide 20g
Hydroquinone 20g
1-phenyl-3-pyrazolidone 2g
Sodium sulfite 30g
N-methylethanolamine 10g
Potassium bromide 2g
Adjust the total volume to 1000 ml with water. Adjust to pH 13.

  The silver image pattern was degreased and then electroless copper plated. The degreasing treatment was carried out at a temperature of 60 ° C. for 1 minute by using a Meltex Co., Ltd. product and a cleaner 160 of 50 g / L. For electroless copper plating, a thin electroless copper plating made by Meltex, Melplate CU-5100 is constructed with a standard dilution, and the dissolved oxygen concentration is adjusted to 5.0 ppm. After performing the plating process for 5 minutes, the conductive material C was produced by immediately performing the plating process at 50 ° C. for 10 minutes in the second plating bath in which the dissolved oxygen concentration was adjusted to 3.0 ppm. In the first plating bath, by using a commercially available air pump, plating is performed by air bubbling at 50 L / min with respect to 100 L of plating solution and at 15 L / min with respect to 1 L of plating solution in the second plating solution. The dissolved oxygen concentration in the liquid was adjusted.

  When this fine wire pattern of the conductive material C was observed at an magnification of 2100 using an optical microscope, 6.2 μm of electroless copper was deposited on a 6.3 μm silver image fine wire, and adjacent wirings were connected. Confirmed not. The electrical resistance value between the two electrodes was measured using FLUKE 70 (trade name of a multimeter manufactured by JOHN FLUKE MFG CO. INC.) And found to be 5.2Ω.

<Comparative example 2>
A comparative conductive material D was produced in the same manner as in Example 2 except that the dissolved oxygen concentration in the first plating bath was adjusted to 3.0 ppm in the electroless copper plating of Example 2 above. When the fine line pattern of the electroconductive material D after plating was observed with an optical microscope at a magnification of 2100 times, 11.8 μm of electroless copper was deposited on the 6.3 μm silver image fine line and adjacent to it. It was observed that the wiring was connected in some places. Moreover, when the resistance value between two electrodes was measured, it was 1.3Ω. This is because the electrical resistance is lowered because adjacent lines are connected to each other.

<Comparative Example 3>
A comparative conductive material E was produced in the same manner as in Example 2 except that the dissolved oxygen concentration in the second plating bath was adjusted to 5.0 ppm in the electroless copper plating of Example 2 above. When the fine line pattern of the electroconductive material E after plating was observed with an optical microscope at a magnification of 2100 times, 5.5 μm of electroless copper was deposited on the 6.3 μm silver image fine line and adjacent to it. Confirmed that the wiring was not connected. Moreover, when the resistance value between two electrodes was measured, it was 8.1Ω. This is probably because the amount of deposited electroless copper was less than that of the conductive material C.

  A comparative conductive material F was produced in the same manner as in Example 2 except that the dissolved oxygen concentration in the first plating bath was adjusted to 5.5 ppm in the electroless copper plating of Example 2 above. When the fine line pattern of the conductive material F after plating was observed with an optical microscope at a magnification of 2100 times, 6.0 μm of electroless copper was deposited on the 6.3 μm silver image fine line and adjacent to it. Confirmed that the wiring was not connected. Moreover, it was 5.8 (ohm) when the resistance value between two electrodes was measured. This is considered to be because the deposited electroless copper was slightly less than the conductive material C.

  A comparative conductive material G was produced in the same manner as in Example 2 except that the dissolved oxygen concentration in the second plating bath was adjusted to 2.1 ppm in the electroless copper plating of Example 2 above. When the fine line pattern of the electroconductive material G after plating was observed with an optical microscope at a magnification of 2100 times, 6.9 μm of electroless copper was deposited on the 6.3 μm silver image fine line and adjacent to it. Confirmed that the wiring was not connected. Moreover, when the resistance value between two electrodes was measured, it was 4.6Ω. This is thought to be because the line width was somewhat thick due to the deposited electroless copper.

In the light-sensitive material of Example 2, the physical development nucleus layer is not provided, and the silver (silver nitrate) / gelatin mass ratio of the silver halide emulsion in the silver halide emulsion layer is 3.0, the hardener. The photosensitive material used in the above (b) was prepared in the same manner as in Example 2 except that 1,3-divinylsulfonyl-2-propanol was added in an amount of 2% by mass based on gelatin. After that, with a contact printer using the same mercury lamp as the light source as in Example 2, the negative original of the wiring pattern used in Example 2 was brought into close contact and exposed with an energy amount of 0.6 mJ / cm ² , and then Mitsubishi Paper Industries After dipping for 90 seconds at 20 ° C. in a GEKKOL developer, a 3% aqueous acetic acid solution was used as a developing stop solution, and then immersed for 30 seconds at 20 ° C. Further, it was immersed in the following fixing solution-1 at 20 ° C. for 3 minutes and then washed with running water for 5 minutes to obtain a silver image pattern in which a silver wiring pattern was formed by the above-mentioned (b). Thereafter, in the same manner as in Example 2, after the plating treatment was performed at 50 ° C. for 5 minutes in the first plating bath in which the dissolved oxygen concentration was adjusted to 5.0 ppm, the dissolved oxygen concentration was immediately adjusted to 3.0 ppm. Plating treatment was performed at 50 ° C. for 10 minutes in a two-plating bath to produce the conductive material H of the present invention.

<Fixing solution-1>
200 g of N-aminoethylethanolamine
Sodium thiosulfate pentahydrate 5g
Anhydrous sodium sulfite 15g
Adjust the total volume to 1000 ml with water. Adjust to pH 10.5.

  When the fine line pattern of the electroconductive material H after plating was observed at a magnification of 2100 using an optical microscope, 6.1 μm of electroless copper was deposited on the 6.3 μm silver image fine line and adjacent to it. Confirmed that the wiring was not connected. Moreover, it was 6.5 (ohm) when the electrical resistance value between two electrodes was measured.

<Comparative example 4>
A comparative conductive material I was prepared in the same manner as in Example 5 except that the dissolved oxygen concentration in the first plating bath was adjusted to 3.0 ppm in the electroless copper plating of Example 5. When the fine line pattern of the electroconductive material I after plating was observed with an optical microscope at a magnification of 2100 times, 11.5 μm of electroless copper was deposited on the 6.3 μm silver image fine line and adjacent to it. It was observed that the wiring was connected in some places. Moreover, when the resistance value between two electrodes was measured, it was 1.4Ω. This is because the electrical resistance is lowered because adjacent lines are connected to each other.

<Comparative Example 5>
A comparative conductive material J was produced in the same manner as in Example 5 except that the dissolved oxygen concentration in the second plating bath was adjusted to 5.0 ppm in the electroless copper plating of Example 5. When the fine line pattern of the electroconductive material J after plating was observed with an optical microscope at a magnification of 2100 times, 5.4 μm of electroless copper was deposited on the 6.3 μm silver image fine line and adjacent to it. Confirmed that the wiring was not connected. Moreover, when the resistance value between two electrodes was measured, it was 8.3Ω. This is presumably because the amount of deposited electroless copper was less than that of the conductive material H.

  As can be seen from these results, after forming a silver image on at least one surface of the support, the silver image was subjected to a first plating bath in which the dissolved oxygen concentration in the electroless copper plating solution was 4 ppm or more. By performing plating treatment, and then performing plating treatment in the second plating bath in which the dissolved oxygen concentration in the electroless copper plating solution is less than 4 ppm, the thickness of the wiring width due to electroless copper plating is improved and excellent A conductive material having high conductivity can be obtained.

Claims (1)

  After forming a silver image on at least one surface on the support, the silver image is subjected to plating treatment in a first plating bath having a dissolved oxygen concentration of 4 ppm or more in the electroless copper plating solution, and then electroless A method for producing a conductive material, comprising performing a plating treatment in a second plating bath having a dissolved oxygen concentration in a copper plating solution of less than 4 ppm.