JPH0360110B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an image forming method using an image forming material of the type that obtains a visible image by physical development. Physical development is a visible image made of metal particles grown by treating fine metal nuclei forming a latent image with a developer containing reducible metal ions and a reducing agent (hereinafter often referred to as "physical developer"). It is generally known as a means of forming silver images. In recent years, non-silver salt image forming materials have been reconsidered due to the limited resources of silver salts, but the ones that have been put into practical use as image forming methods that utilize physical development are:
There is only a method for forming conductor patterns on printed circuit boards. An image forming method using physical development that has been proposed so far utilizes the reaction of ferric ions to become ferrous ions when irradiated with light.
There is a method of reducing noble metal ions with iron ions to create metal development nuclei and physically developing them. Development nucleation systems used in this method include iron-gold system,
There are iron-mercury-based, iron-silver-based (that is, systems that give brown prints), and the like. Furthermore, a method using an organic compound as a photoreducing agent has also been proposed. For example, one method uses a photosensitizer system consisting of a combination of a diazosulfonate and a nucleating water-soluble mercury compound;
When exposed to this system, the sulfite ion of the diazosulfonate is liberated, which disproportionates the monovalent mercury salt to form zero-valent mercury, and when exposed to a physical silver developer, silver is deposited on the mercury nucleus. and obtain a visible image. Instead of diazosulfonate, CN ^- ,
It is said that images can also be obtained using photosensitive compounds that liberate CNS ^- , NO ^- , and S ₂ O ₃ ^2- ions. (Japanese Patent Publication No. 37-3319) However, since these methods use mercury, there are problems in waste liquid treatment and operation. Another method is to use a photosensitive system consisting of a combination of a special diazonium salt, such as a hydroxybenzenediazonium salt, and nucleating silver nitrate; upon exposure to this system, the diazonium salt decomposes to form a phenol. Silver nuclei are formed by the reducing power of phenol, and a visible image is obtained by exposing them to a physical silver developer. This is an example using silver. On the other hand, the inventors have already proposed a method of combining physical development and photosensitive resin. That is, in this method, a coated layer of photosensitive resin is exposed and developed, the resin is selectively eluted to form a relief image, metal nuclei are included in the relief image, and then physical development is performed. In order to form metal nuclei in the relief image, for example, the relief image is first treated with an acidic aqueous solution of palladium chloride and then with an acidic aqueous solution of stannous chloride to form metal palladium nuclei. This method uses the relief pattern forming ability of the photosensitive resin itself to pattern a metal latent image, but since it is a relief image, it has the disadvantage of not being able to obtain sufficient resolution and the film strength. has a weak disadvantage. In addition, titanium oxide (U.S. Patent Nos. 2,738,272 and 2,929,709), anthraquinone (U.S. Pat. No. 2,504,593), tin chloride (Plating 58,786 (1971)), etc. are used as photoreducing substances. Methods are also known and have been put into practical use, but all of these methods are used only as methods for forming patterns on printed circuit boards. When using titanium oxide, it is difficult to obtain a transparent non-image area, and anthraquinone-2,
Sodium 6-disulfonate has already been put to practical use in the production of printed circuit boards, but this is limited to combinations of divalent copper salts such as copper formate and copper gluconate with nickel chloride, cobalt chloride, and iron sulfate. It is being Also, when using tin chloride, stannous chloride
Problems include that tin is easily oxidized by oxygen in the atmosphere, has a short lifespan, and that a powerful light source cannot be used because the photosensitive wavelength is around 250 nm. The inventors further discovered that gold, platinum palladium, silver,
It has also been proposed that physical development using a metal nucleus such as iron or copper as a development nucleus is inhibited by a compound having a diazo group or an azide group, but the mechanism of such inhibition is not clear, but It can be presumed that physical development is effectively suppressed by the compounds themselves having , or the reaction products obtained by treating these compounds with a physical developer, and the structure of the compound obtained by this physical developer treatment. Although it is not clear whether the compound has a diazo group or azide group is not decomposed by light after physical development, it is presumed that some kind of chemical change has occurred, and while this can be effectively suppressed, This causes fatigue of the physical developer due to the reaction with the physical developer, and if physical development is performed repeatedly using the same physical developer, the time required for physical development will gradually increase, or the physical development may be incomplete. This method has drawbacks such as the density of the visible image not increasing as the image ages, and pinholes forming in the visible image area. The present invention eliminates the drawbacks of the above-mentioned suppression by a photo-crosslinking agent, and specifically, after pattern exposure, the photo-crosslinking agent in unexposed areas is removed, and then physical development is performed. In the image forming layer,
A first development step (metal development nucleus formation step) of performing pattern exposure, then dissolving and removing the photocrosslinking agent in the unexposed areas, and then bringing the image forming layer into contact with a reducing agent to form image formation nuclei; The image forming layer is brought into contact with a physical developer containing reducible metal ions and a reducing agent, and metal particles are deposited and grown in unexposed areas by reduction of the reducible metal ions, centering on metal development nuclei. This is characterized in that a second development step (physical development step) is performed to form an image. In this case, the first development step and the second development step are considered to proceed sequentially in terms of reaction mechanism, but operationally, they may be carried out sequentially in this order, or they may be carried out in a physical developer. It is also possible to carry out substantially simultaneously by using a relatively strong reducing agent. The pattern exposure step in the image forming method of the present invention has the effect of increasing the degree of crosslinking of the hydrophilic binder layer in the exposed portion of the image forming layer and reducing its physical development effect. Therefore, in the subsequent physical development, in the presence of metal development nuclei,
The rate at which metal ions in the physical developer precipitate and grow as metal is lower than that in unexposed areas, making it difficult for such metal precipitation to occur.As a result, visible particles consisting of metal particles that selectively grow in unexposed areas An image is obtained. In this way, conventionally, metal development nuclei were generated in the exposure process, but in the present invention, metal development nuclei are generated through reduction treatment regardless of exposure, and in the exposure process, metal development nuclei are generated by the reduction process, which is caused by the penetration of the physical developer. The most important feature of the image forming method of the present invention is that it provides a difference in speed. The present invention will be explained below with reference to the drawings. In the following description, "%" and "part" are
Unless otherwise specified, measurements are based on weight. FIG. 1 is a sectional view in the thickness direction conceptually showing one embodiment of the image forming material of the present invention. As an example is shown in FIG. 1, the image forming material A of the present invention comprises a support 1 and an image forming layer 2 provided thereon. As the support 1, any solid material such as glass, wood, paper, plastic film, woven fabric, non-woven fabric can be used, and among them, plastic films such as polyester film and triacetate film are particularly preferably used. These supports 1 are provided with the image forming layer 2 after being pretreated to improve adhesion, such as corona discharge treatment and primer treatment, if necessary. The image forming layer 2 is formed by dispersing, preferably dissolving, in a hydrophilic binder layer, a metal compound that is reduced to become metal development nuclei and a photocrosslinking agent. Examples of binders include natural polymers such as gelatin, casein, glue, gum arabic, and shellac, carboxymethylcellulose, egg albumin, polyvinyl alcohol (partially saponified polyvinyl acetate), polyacrylic acid, polyacrylamide, polyvinylpyrrolidone, and polyvinyl pyrrolidone. Ethylene oxide, maleic anhydride copolymers, etc. are used, but other resins than the above can also be used as long as they are water-soluble or hydrophilic resins. The degree of hydrophilicity required for the binder is such that when the image forming layer 2 is formed and brought into contact with a physical developer, the physical developer permeates into the image forming layer 2 to enable physical development. Metal compounds that are reduced to give metal development nuclei include water-soluble salts such as chlorides and nitrates of noble metals such as palladium, gold, silver, platinum, and copper, such as those contained in the activator solution for electroless plating. Water-soluble salts such as palladium chloride, silver nitrate, and gold tetrachloride are used. Among these, water-soluble salts of palladium, gold, platinum, and copper, particularly water-soluble salts of palladium, are preferably used. The image forming layer 2 is preferably formed by mixing an aqueous solution of the above-mentioned metal compound (a commercially available activator liquid for electroless plating can be used as is) with an aqueous binder solution together with a photocrosslinking agent to obtain a viscosity suitable for coating. A liquid having a thickness of about 10 to 1000 centipoise is prepared, and this is applied onto the support 1 and dried to obtain a coating film having a thickness of usually 0.1 to 30 μm. In addition to the water mentioned above, a mixed solvent of water and a water-miscible solvent such as a lower alcohol, ketone, or ether may also be used as the solvent. Examples of the photocrosslinking agent include water-soluble zinc chloride double salts, sulfates, and phosphates having a diazo group, or diazo resins obtained from these, and more specifically, p-N,N-diethylaminobenzenediazonium chloride. Zinc chloride double salt, p-N-ethyl-N-β-hydroxyethylaminobenzenediazonium chloride zinc chloride double salt, p-N,N-dimethylaminobenzenediazonium chloride zinc chloride double salt, 4-morpholinobenzenediazonium chloride Zinc chloride double salt, 4-morpholino-
2,5-diethoxybenzenediazonium chloride zinc chloride double salt, 4-morpholino-2,5-dibutoxybenzenediazonium chloride zinc chloride double salt, 4-benzoylamino-2,5-diethoxybenzenediazonium chloride zinc chloride double salt ,
4-(4'-methoxybenzoylamino)-2,5-
Diethoxybenzenediazonium chloride zinc chloride double salt, 4-(p-tolylmercapto)-2,5
-Dimethoxybenzenediazonium chloride zinc chloride double salt, 4-diazodiphenylamine zinc chloride double salt, 4-diazo-4'-methoxydiphenylamine zinc chloride double salt, 4-diazo-3-methoxy-diphenylamine zinc chloride double salt , sulfates and phosphates corresponding to the zinc chloride double salts, diazo resins which are reaction products of these diazonium compounds and paraformaldehyde, and azide compounds such as p-azidobenzaldehyde and p-azide. Acetophenone, p-azidobenzoic acid, p-azidobenzalacetophenone, p-
Azidobenzalacetone, 4,4'-diazidochalcone, 2,6-bis-(4'-azidobenzal)-acetone, 4,4'-diazidostilbene-2,2'-
Disulfonic acid, p-azidobenzoyl chloride,
3-azido phthalic anhydride, 4,4'-diazido diphenyl sulfone, p-azido cinnamic acid, sodium 4,4'-diazidobenzoylacetone-2,2'-sulfonate, etc. are used. The image forming layer 2 contains 0.1 to 100 parts of a metal compound, particularly 1 to 10 parts of a metal compound per 100 parts of the above-mentioned binder.
It is preferable to include a photocrosslinking agent in an amount of 1 to 100 parts, particularly 20 to 60 parts. After forming the image forming layer 2, a hardening process is desirably performed in order to suppress elution of the binder into the developer during physical development. For hardening, for example, the following compound is mixed in the coating solution for forming the image forming layer 2 at a ratio of 0.1 to 50 parts per 100 parts of the binder, or an aqueous solution thereof is applied onto the image forming layer. This is done by Al compounds such as potassium alum and ammonium alum; Cr compounds such as chromium alum and chromium sulfate;
Aldehydes such as formaldehyde, glyoxal, glutaraldehyde, 2-methylglutaraldehyde, succinaldehyde; O-benzoquinone, p-benzoquinone, cyclohexane-1,2
-dione, diketones such as cyclopentane-1,2-dione, diacetyl, 2,3-pentanedione, 2,5-hexanedione, 2,5-hexenedione; epoxides such as triglycidyl isocyanurate; tetraphthaloyl Chloride, 4,4'-
diphenylmetadisulfonyl chloride, 4,
Acid anhydrides such as 4'-diphenylmethanedisulfonyl chloride; tannic acid, gallic acid, 2,4-
Dichloro-6-hydroxy-S-triazine, as well as general formulas R ₂ NPOX ₂ , (R ₂ N) _o POX _3-o ,

【formula】

[Formula] and R-N=C=N-R' (where R is carbon 2-
6 alkyl group, R′ is (CH ₃ ) ₃ N+(CH ₃ ) ₃ X ^- group,
X is F or Cl; Resins such as maleic acid copolymers, methacrylic acid/methacrylonitrile copolymers, polymethacrylamide, and methacrylic acid ester copolymers. Glutaric acid, succinic acid as dicarboxylic acids, malic acid as hydroxycarboxylic acids,
Organic carboxylic acids such as lactic acid, citric acid, aspartic acid, glycolic acid, and tartaric acid can also be used. According to the image forming method of the present invention, the image forming layer 2 is first subjected to pattern exposure through a transparent original 3 as shown in FIG. 2, for example. As a result, the photocrosslinking agent is selectively decomposed and crosslinked in the exposed area 2A to a degree corresponding to the amount of exposure. As the light source, any light source can be used as long as it can destroy the photocrosslinking agent described above. For example, ultra-high pressure mercury lamps, high pressure mercury lamps, low pressure mercury lamps, metal halide lamps, arc lamps,
Chemical lamps, xenon lamps, Ar lasers, etc. can be used. Depending on the desired image gradation, for example, when using ultraviolet light with a center wavelength of 405 nm, the
It is sufficient to expose for 10 to 200 seconds at an intensity of ^m3 to 300w/ ^m3 . Due to the pattern exposure described above, the photocrosslinking agent is decomposed in the exposed area 2A, and the hydrophilic binder is crosslinked in the exposed area 2A and is imparted with hydrophobicity. The photo-crosslinking agent remains unchanged in the unexposed area, which is the area that has not been exposed by the above pattern exposure, so if the photo-crosslinking agent in the unexposed area is left as is and subsequent development is carried out, a physical developer is used. The photocrosslinking agent in the unexposed area must be dissolved and removed because the fatigue of the photocatalyst is accelerated. Dissolution and removal may be carried out by immersing the image forming layer in water or by bringing it into contact with water, and the time required for the treatment varies depending on the material of the hydrophilic binder layer, but is generally 5 to 30 minutes. Then, through pattern exposure, an aqueous reducing agent solution is brought into contact with the image forming layer 2 having a latent image imparted with hydrophobicity in a pattern by dipping or coating, thereby almost uniformly developing the metal into the image forming layer 2. Generate a nucleus. Examples of reducing agents include stannous chloride, stannous sulfate, sodium borohydride, dimethylamine borazane, diethylamine borazane, trimethylamine borazane, other borazane derivatives, borane derivatives such as borane, diborane, and methyldiborane, hydrazine, etc. can be used. Particularly preferably, an acidic stannous chloride solution, a stannous sulfate solution (Weiss solution), or a commercially available sensitizer solution for electroless plating is used, but in general, any strong reducing agent can be used. This reduction treatment generally uses a reducing agent solution containing a reducing agent at a concentration of 0.1 to 50 g, and is performed for 10 seconds or more at room temperature or under heating, although it varies depending on the strength of the reducing agent.
It takes about 400 seconds. Furthermore, the image forming layer 2 having a latent image with high crosslinking density due to selective decomposition of the metal development nuclei and photocrosslinking agent obtained in this way and imparted with hydrophobicity is coated with a physical developer by dipping or coating. When brought into contact, a visible image 2B as shown in FIG. 3 is formed in which the metal in the developer is precipitated by reduction centering on the metal development nuclei in the unexposed area. As the physical developer, an aqueous solution containing a water-soluble reducible heavy metal salt and a reducing agent is used, if necessary, in a heated state. Examples of reducible heavy metal salts include nickel,
Group VIb metals such as cobalt, iron and chromium, copper etc.
Water-soluble salts of Group Ib metals are used alone or in mixtures. As suitable water-soluble reducible heavy metal salts, for example, the following can be used. Heavy metal halides such as cobaltous chloride, cobaltous iodide, ferrous bromide, ferrous chloride, chromic bromide, chromic iodide, cupric chloride; nickel sulfate, ferrous sulfate , heavy metal sulfates such as cobaltous sulfate, chromic sulfate, cupric sulfate; heavy metal nitrates such as nickel nitrate, ferrous nitrate, cobaltous nitrate, chromic nitrate, cupric nitrate; ferras Organic acid salts of heavy metals such as acetate, cobalt acetate, chromic acetate, and chromic fluorate. These reducible heavy metal salts are contained in the physical developer at a rate of, for example, 10 to 100 g/g/. Examples of reducing agents include hypophosphorous acid, sodium hypophosphite, sodium borohydride, hydrazine, formalin, diethylamine borane, dimethylamine borane, trimethylamine borane, borane, diborane, methyldiborane, diborazane,
Borazane, borazine, t-butylamine borazane, pyridine borane, 2,6-lutidine borane,
Ethylenediamineborane, hydrazinediborane,
Dimethylphosphine borane, phenylphosphine borane, dimethylaldine borane, phenylaldine borane, dimethylstipine borane, diethylstipine borane, etc. can be used. These reducing agents can be added to the physical developer, for example.
It is used at a rate of 0.1 to 50g/. Some of the reducing agents available in the physical developer are those for the generation of metal development nuclei. Therefore, when using a physical developer containing a relatively strong reducing agent, the reduction treatment for generating metal development nuclei is not performed after exposure, and the process is directly performed with the physical developer to prevent the generation of metal development nuclei. It is also possible to perform both physical development and physical development substantially simultaneously. However, if the reaction is carried out in two stages, there is an advantage that the reduction reaction and the metal precipitation reaction can be controlled accurately by adjusting the temperature and reaction time, respectively. In particular, in the image forming method of the present invention, if the development time is prolonged, the physical developer will penetrate not only the unexposed areas but also the exposed areas, causing so-called fog, so a two-step process is preferable. In order to prevent heavy metal ions generated by dissolving the above-mentioned reducible heavy metal salts from precipitating as hydroxides, the physical developer contains, for example, monocarboxylic acids; dicarboxylic acids; hydroxyl acids such as malic acid and lactic acid. Carboxylic acid; may contain one or more complexing agents consisting of organic carboxylic acids such as succinic acid, citric acid, aspartic acid, glycolic acid, tartaric acid, ethylenediaminetetraacetic acid, gluconic acid, sugar acid, and quinic acid. can. For example, 1 to 100 g of these complex chloride agents may be added to the physical developer.
used at a rate of Furthermore, the physical developer contains PH regulators such as acids and bases, buffers, preservatives, etc. to improve the storage stability and operability of the developer and the quality of the resulting images.
Brighteners, surfactants, etc. are added as necessary according to conventional methods. According to the present invention, since the physical developer is less fatigued, it has the advantage of being able to prolong the time required for physical development, reduce the density of a visible image, and prevent the occurrence of pinholes. With a density of 4 or more, it is possible to form a black image with gradations as required, and because it uses a photocrosslinking agent dissolution system, the resolution is high.
Images that can replace images obtained by silver salt photography are obtained. In addition, since the image is a metal image, Furmar reduction liquid consisting of red blood salt and sodium thiosulfate,
This can be corrected using a reducing fluid such as Kodak R-4. Taking advantage of these characteristics, the image material obtained by the method of the present invention can be used as a substitute for lithographic film or as a mask material. Also,
Physical development is performed, for example, the first development is performed using a nickel plating bath using a boron reducing agent, and the second development is performed using a high-temperature nickel plating bath at 65 to 90°C using a reducing agent containing sodium hypophosphite, or high-speed plating using copper plating. If the conditions are met, a metallic image with metallic luster can be formed on the binder surface. Moreover, the obtained image can be washed with a 5% aqueous solution of, for example, hydrochloric acid or 5% nitric acid.
Since the binder in non-image areas can be selectively removed by processing for minutes, it can also be used as a printed circuit board. Hereinafter, the present invention will be explained in more detail with reference to Examples. Example 1 _{2 g of PdCl 2} was dissolved in 1000 c.c. of water together with 20 ml of HCl, and 20 g of the resulting _two PdCl solutions were used to prepare a sensitive material (coating solution for forming an image forming layer) having the following composition. PdCl ₂ liquid with the above composition 20g Gelatin (Nitta Gelatin P-2151) 30% aqueous solution 10g Diazoresin 20% aqueous solution 2.5g Glutaric acid 0.12g The temperature of the above sensitive material was adjusted to 30°C to 40°C, and plasma treatment was performed in advance. Apply to Natsuta polyester film (Toray Lumirror S 100#) and dry.
A coating film of 5μ was obtained. Sensitive film (image forming material) obtained above
The negative film was closely exposed for 2 minutes using an ultra-high pressure mercury lamp 2KW printer (distance 100cm from the light source), then immersed in water at 20℃ to dissolve and remove the diazoresin, and then immersed in the following reducing bath at 30℃ for 1 minute. and reduced it. SnCl ₂ 1g HCl 40ml H ₂ O 100c.c. Next, it was treated with a physical developer having the following composition at 90°C to precipitate metal and form a black image. Nickel chloride 30g Sodium hypophosphite 10g Sodium oxyacetate 50g Water 900g A similar sensitive film was exposed for 2 minutes using a 2KW ultra-high pressure mercury lamp printer (distance 100cm from the light source) with the negative film in close contact. The film was then immersed in water at 20°C for 20 minutes, and then immersed in a boron-nickel plating bath (Shibanitsukel stock solution, manufactured by Okuno Pharmaceutical Co., Ltd.) at 65°C for 50 seconds, developed, and dried without any special reduction treatment. The resulting image was black with 150 lines and 4% halftone dots resolved. In this development process, reduction and development are performed simultaneously. Example 2 A sensitive film was prepared in the same manner as in Example 1,
After exposure through a negative film and immersing it in water at 20°C, it was developed by immersing it in a physical developer having the following composition at 30°C for 1 minute and 30 seconds to obtain a black image. Nickel chloride 0.1 mol Dimethylamine borane 0.1 mol Succinic acid 0.5 mol The pH was adjusted to 7.0 with NaOH. Example 3 A sensitive film was prepared in the same manner as in Example 1, exposed to light, washed with water, and mixed with a physical developing solution (Narcuss) obtained by mixing liquids A and B having the following composition at a ratio of 1:1 immediately before use. The film was developed by immersing it in an electroless plating bath (electroless plating bath) at 22°C for 7 minutes to obtain a black image. Solution A Copper sulfate 60g / Nickel sulfate 15g / Hydrazine sulfate 45g / Solution B Sodium hydroxide 45g / Potassium sodium tartrate 180g / Sodium carbonate 15g / Example 4 A sensitive film prepared in the same manner as Example 1 was washed with water and dried. Expose for 2 minutes using a high-pressure mercury lamp 2KW printer (distance 100cm from the light source) and 30 minutes with running water.
After washing with water, hydrazine hydrochloride (N ₂ H ₂ · HCl)
The sample was immersed for 1 minute at 40°C in a reduction bath containing 1.0 mol of Then, it was treated with an electroless plating solution shown below for 6 minutes to obtain an image with metallic luster. Nickel chloride 50g / Sodium hypophosphite 10g / Sodium citrate 10g / Similarly, the sensitive film of Example 1 was heated using an ultra-high pressure mercury lamp.
Using a 2KW printer (distance 100cm from the light source), expose for 2 minutes, wash with running water for 30 minutes,
1.0 mol of N ₂ H ₂ HCl/40℃ depending on concentration and solution
The film was then treated with an electroless plating solution having the composition shown below and having a pH of 5.5 at 21°C for 1 minute and 30 seconds. Nickel hypophosphite 26g/boric acid 12g/ammonium sulfate 2.6g/sodium acetate 20g/A uniform black image was obtained by the above operations. Example 5 A photosensitive material was prepared with the following composition using a PdCl _{dihydrochloric} acid aqueous solution prepared in the same manner as in Example 1, and then coated on a polyester film in the same manner as in Example 1, and dried to form a photosensitive material. A film was produced. PdCl _{dihydrochloric} acid aqueous solution (Nippon Kanizen) 20g Gelatin (Nitta Gelatin p-2151) 30% aqueous solution 10g Diazoresin 20% aqueous solution 2.5g Glutaraldehyde 50% aqueous solution 0.05g After exposing the negative film for 2 minutes using a camera (distance 100cm) and washing it under running water for 30 minutes,
It was immersed in a boron-nickel bath (Shibanitsukel stock solution, manufactured by Okuno Pharmaceutical Co., Ltd.) at 100°C for 100 seconds, developed, and dried. Although the development time is longer than in Example 1, the film has good adhesion and does not peel off even if the film surface is rubbed by hand during development. The image quality was good, resolving 150 lines and 4% halftone dots. Example 6 A sensitive material was prepared with the following composition and used in Example 1.
A sensitive film was prepared in the same manner. PdCl _{dihydrochloric} acid aqueous solution (Nippon Kanigen Retschuma) 20g PVA (Nippon Synthetic Gohsenol NH-14) 10% aqueous solution 20g Diazolene 20% aqueous solution 2.5g Malic acid 0.08g The above photosensitive film was heated with a diazocopy lamp (Ricoh Hi-Start 4). Expose for 40 seconds by overlaying with negative film, rinse with running water for 30 minutes, and remove SnCl ₂ 1.
% hydrochloric acid aqueous solution (Nippon Kanigen Pink Shauma) for 1 minute at room temperature to form physical development nuclei on the entire surface. Next, as a physical development bath, hypophosphorous acid-based electroless plating solution Blue Syumer (manufactured by Okuno Pharmaceutical Co., Ltd.) was used.
It was processed at ℃ for 1 minute and 30 seconds to obtain a black image in the exposed area. Similarly, even if the above-mentioned sensitive film is pre-treated in the above-mentioned reducing bath, washed with water, dried, pattern-exposed using a diazocopy lamp, and then developed using a blue chemist, there will be no black color in the exposed areas. Got the image. After exposure, the above-mentioned sensitive film was treated with running water for 30 minutes, and then the following developing bath (pH adjusted to 12.5 with NaOH, temperature 40-50
℃) for 2 minutes, reduction and physical development were performed in one bath, and a good black image was obtained. Nickel sulfate 20g Potassium sodium tartrate 40g Sodium borohydride 2.3g Water 1000g Example 7 A photosensitive film was prepared in the same manner as in Example 1 using the sensitive material having the composition shown below. HAuCl ₄・4H ₂ O1% hydrochloric acid aqueous solution 20g Gelatin (Nitta gelatin p-2222) 30% aqueous solution
6.7g Diazoresin 20% aqueous solution 2.5g Tartaric acid 0.05g Exposure conditions, water washing conditions, reduction bath conditions, and development bath conditions were all the same as in Example 1. As a result, black color was obtained by using any of the three methods. An image is obtained. Example 8 A photosensitive material was prepared with the following composition, and a photosensitive film was prepared in the same manner as in Example 1. Redshumer 20g Gelatin (p-2152B Nitta Gelatin) 20% aqueous solution 6.7g 4,4'-Diazidodiphenylsulfone 20% aqueous solution 2.0g Mucochloric acid 0.06g Exposure conditions, water washing conditions, reduction conditions, and development conditions are all examples. As a result of carrying out the same procedure as in 1, a black image was obtained using any of the three methods.

[Brief explanation of drawings]

FIG. 1 is a schematic cross-sectional view in the thickness direction showing the laminated structure of the image forming material of the present invention, and FIGS. 2 and 3 show intermediate steps of the image forming method of the present invention using the image forming material shown in FIG. FIG. 1...Support, 2...Image forming layer, 2A...Exposed area, 2B...Visible image, 3...Transparent original, A...
Imaging materials.

Claims (1)

[Scope of Claims] 1 Image formation comprising an image forming layer provided on a support, and a hydrophilic binder layer containing a photocrosslinking agent and a metal salt that becomes metal development nuclei when the image forming layer is reduced. pattern-exposing the image forming layer of the material to react the photocrosslinking agent in the exposed areas to crosslink the hydrophilic binder layer in the exposed areas, and then dissolving and removing the photocrosslinking agent in the unexposed areas; Thereafter, the image forming layer is brought into contact with a reducing agent to form metal development nuclei in the image forming layer, and the image forming layer is subjected to physical development containing reducible metal ions and a reducing agent. A second developing step is performed in which an image is formed in the unexposed area by bringing the metal particles into contact with a liquid, and the metal particles are precipitated and grown by reduction of the reducible metal ions in the unexposed area. image forming method. 2. The image forming method according to claim 1, wherein the photocrosslinking agent is composed of a single compound or a mixture of compounds having a diazo group or an azide group.