JPS6335016B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image forming method, and particularly to a silver complex diffusion transfer method, a photographic material used therein, a method for manufacturing the same, and further uses of the photographic material.
More specifically, the present invention relates to a method and materials for obtaining high-density images using extremely small amounts of silver halide.

The principle of silver complex diffusion transfer method (hereinafter referred to as DTR method) is described in US Pat. No. 2,352,014 and is well known.

In the DTR process, silver complex salts are imagewise transferred by diffusion from a silver halide emulsion layer to an image-receiving layer, and they are converted into a silver image, often in the presence of physical development nuclei. For this purpose, an imagewise exposed silver halide emulsion layer is placed in contact with, or brought into contact with, an image-receiving layer in the presence of a developing agent and a silver halide complexing agent, and the unexposed Converts silver halide to soluble silver complex salt.

In the exposed parts of the silver halide emulsion layer, the silver halide is developed to silver (chemical development);
Therefore, it cannot be dissolved further and therefore cannot be diffused.

In the unexposed portions of the silver halide emulsion layer, the silver halide is converted to soluble silver complex salts, which are transferred to the image-receiving layer where they form a silver image, usually in the presence of development nuclei.

In a direct positive silver halide emulsion, the effects of silver halide in exposed and unexposed areas are reversed.

The DTR method is used to reproduce documents, create lithographic printing plates,
It can be used in a wide range of applications, including the production of block printing materials and instant photography.

As mentioned above, in the DTR method, a silver halide emulsion layer and an image-receiving layer are provided on separate supports, and during diffusion transfer development, both materials are brought into close contact to form a silver image on the image-receiving material. A so-called "monosheet" type in which an emulsion layer and an image-receiving layer are usually provided adjacent to each other on the same support are known.

The so-called "block printing materials" required in the intermediate process of making printing plates, such as the image-receiving materials for the two types mentioned above, such as block printing materials or phototypesetting paper (usually not using the DTR method), are of high quality. It is necessary to have high density, high contrast, and also high sensitivity, and for this reason, the amount of silver used has increased considerably, although it varies depending on the application. However, there is now a demand for effective use of precious silver resources, and from an economic standpoint, there is also a demand for a technology that uses as little silver as possible.

An object of the present invention is to provide an image forming method that can obtain images with high reflection density by using a very small amount of silver, and materials used therein.

Another object of the present invention is to provide an image forming method and materials used therein that are capable of obtaining images with high sensitivity, high reflection density, high sharpness, and high contrast even when a very small amount of silver is used. It is in.

Further objects and advantages of the present invention will be understood from the following description of the specification.

The above object of the present invention is to provide an opaque support having at least an image-receiving layer containing physical development nuclei for image-wise diffusion transfer and development of a soluble silver complex salt from a silver halide emulsion layer as a silver supply source. The image-receiving layer contains colorants such as pigments and dyes that do not wash out or disappear during photographic processing, and the colorants have a contrast or brightness with the color of the opaque support. It has been found that this can be achieved with a material characterized in that the color is sufficiently large and contains a sufficient amount that the color of the opaque support is substantially masked. According to a preferred embodiment of the invention, there is provided a photographic material comprising at least an image-receiving layer containing a sufficient amount of a black pigment, such as carbon black, on a white paper support coated on both sides with polyethylene containing titanium dioxide. Ru.

According to another preferred embodiment of the invention, titanium dioxide is deposited on an opaque support pigmented to a sufficient concentration with a black pigment, such as carbon black, in an amount sufficient to substantially mask the color of said support. A photographic material is provided which is provided with at least an image-receiving layer containing a white pigment. In the DTR method, the transferred silver image obtained with an unfogged emulsion is usually a positive image of the subject.

The two preferred embodiments described above have the advantage that a positive image or a negative image of the subject can be obtained respectively through the same photographic processing.

Furthermore, in the two preferred embodiments described above, both positive and negative images of the subject can be obtained by using the same material and changing the photographic processing method. For a better understanding, aspects of the present invention will be described with reference to the drawings. The drawings are exaggerated for clarity.

FIG. 1 shows an example of an image-receiving material in as many as two types. The support 1 is, for example, a support colored black, and the image-receiving layer 2 contains a white pigment dispersed therein as a color having a large contrast to the black of the support 1. The white pigment must be used in an amount sufficient to at least make the color of the support 1 invisible. It means the amount necessary to create sufficient contrast with the black color of the support 1 for use as a background non-image area, and does not require an amount that completely masks the black color of the support 1.
Of course, it is more preferable to use an amount that completely masks. The support 1 is preferably colored with a black pigment such as carbon black in order to be used as an image area.

As the support, "ordinary opaque supports" such as baryta paper, polyolefin resin laminated paper, polystyrene, polypropylene, synthetic paper, or sheets of these coated with polyethylene resin are used. In addition, transparent supports such as nitrocellulose, acetylcellulose, polyvinyl acetal, and polyethylene terephthalate films may also contain an opacifying agent therein, or a subbing layer containing an opacifying agent may be formed between the transparent support and the image-receiving layer. It can be used as an opacifying support by disposing it as a subbing layer or an interlayer. This opacifying agent-containing layer can also be provided on the above-mentioned common opaque support to provide the opaque support of the present invention.

In the present invention, the term opaque support has a self-evident meaning well known to those skilled in the art for recognizing photographic images by reflected light, and must be specifically defined as: When an opacifying agent-containing layer is provided below the image-receiving layer, this is meant to include it. When an opacifying agent is used in the support, it is preferable that the opacifying agent also functions as a coloring agent for the support in relation to the coloring agent for the image-receiving layer, except in special cases.
In many cases, the opacifier is a coloring agent such as a black pigment or dye that has a large contrast to the white pigment or dye of the image-receiving layer and is used to form a black opaque support. When the image-receiving layer contains a black coloring agent, the support may be the ordinary opaque support mentioned above, but therein, for example, a resin such as a polyolefin resin or a polypropylene film sheet for coating paper is used. As is well known, those mixed with a white pigment such as titanium dioxide are preferably used. In this case the white pigment functions more as a brightening colorant than as an opacifying agent. However, when these white pigments are contained in the transparent film or its opacifying agent-containing layer, the white pigments function as an opacifying agent as well as a white coloring agent for the black image-receiving layer. As can be understood from the foregoing description, an opaque support is used in the present invention, so that in contrasting the opaque support and the image-receiving layer, in some cases one will be the image area and the other will be the non-image area. In some cases, the image area and the non-image area are reversed. The image area usually contains a black colorant, but since it is contained in the opaque support or image-receiving layer, it rarely causes adverse photographic effects such as excessive desensitization and fog. It is possible to use a large amount of the material, without any need for it, and therefore to obtain an arbitrarily high density, and to obtain an image with high sharpness and high contrast based on the DTR method.

As described above, the support 1 and the image-receiving layer 2 in FIG. 1 may be white opaque supports, and the image-receiving layer may contain a black pigment such as carbon black.

Until now, it has been explained as the most preferable embodiment that the colors of the support and the image-receiving layer are white and black (of course, the main purpose is to use a coloring agent instead of a silver image), but the reflective image is Depending on the color sensitivity of the light-sensitive material used for photography, in manuscript materials that are used for photography, such as printing materials, if there are two different colors with high brightness or contrast, especially white and black. Although it can be used without limitation, it is preferable to use a black colorant in either the opaque support or the image-receiving layer. For example, in addition to the combination of white and black, combinations of black and warm colors such as yellow, orange, and red, and combinations of white and cool colors such as blue, purple, brown, and green are preferable; Combinations of colors (as bright as possible), white and warm colors, and warm colors and cool colors can also be used depending on the purpose and application.

Coloring agents such as pigments and dyes that can be used are well known to those skilled in the art, and examples include carbon black, furnace black, titanium dioxide, barium sulfate, barium carbonate, calcium carbonate, zinc white, lead sulfate, zinc sulfide, and iron. Black (Fe ₃ O ₄ ), yellow lead,
Zinc yellow, yellow iron oxide (FeO(OH)・NH ₂ O), naphthol yellow S, Hansa yellow 10G, permanent orange, iron oxide, red lead (Pb ₃ O ₄ ), permanent orange, brilliant bright scarlet, cobalt purple, Pigments such as ultramarine, navy blue, phthalocyanine blue, zinc green, emerald green, ultramarine, malachite green,
There are dyes such as crystal violet or cyanine and merocyanine which are known as antihalation agents. The dye coloring agent is fixed with a mordant or the like to prevent it from flowing out during processing. When used as a support, it may be mixed therein. Dye colorants that completely run off or disappear during processing cannot be used, but can be used for other purposes, such as antihalation, if the support is such that the color of the image-receiving layer can be distinguished by other means. For this purpose, dyes that discolor or flow out may also be used in areas other than the image-receiving layer. Therefore, in the claims, the color of the opaque support in contrast to the color of the image-receiving layer, which remains essentially unchanged by processing, should be interpreted as the color obtained after processing.

Although the amount of colorant to be used cannot be absolutely defined depending on its type, color combination, etc., in the case of a combination of white and black, the amount used should be such that the difference in optical reflection density is 0.6 or more, preferably 1.0 or more. is desirable. In the case of other colored colorants as well, the difference in optical reflection density at their main absorption wavelength can be determined using the above-mentioned value as a guide, and it can be determined by a simple experiment. However, since the coloring agent for the image-receiving layer needs to substantially mask the color of the support, it is not preferable to use a highly transparent coloring agent, that is, a coloring agent having a small optical refractive index alone.

Coloring agents are non-particulate materials such as dyes and
Pigments on the order of 0.01 to 10 microns may be used, although larger ones may also be used. Although it varies depending on the pigment, an amount of about 0.1 to 30 g/m ² can be used in the image-receiving layer.

1A shows a state in which soluble silver complex salt is diffusely transferred from a silver halide emulsion layer provided on another support to the image-receiving layer 2 and developed (shaded area). The image-receiving layer contains well-known physical development nuclei such as sulfides or selenides of metals such as gold, silver, platinum, palladium, cadmium, zinc, nickel, cobalt, lead, and copper, as well as fine particles of noble metals. .

Physical development nuclei can also be obtained by the above-mentioned coloring agents, which may also serve as the coloring agent in some cases, by depositing a trace amount of a noble metal, such as silver, on a pigment such as carbon black or titanium dioxide ( whiteness is not impaired).

The hydrophilic colloid binder used in the image-receiving layer is preferably a protein-like material such as gelatin and related materials, which may be partially or completely combined with other photographic binders such as colloidal albumin, casein, carboxymethyl cellulose, hydroxyethyl cellulose. It can be replaced with cellulose derivatives such as agar, agar, sodium alginate, sugar derivatives such as starch derivatives, synthetic hydrophilic colloids such as polyvinyl glycol, poly-N-vinylpyrrolidone-polyacrylic acid copolymer, polyacrylamide, and the like. The thickness of the image receiving layer is
The thickness is about 0.5 to 50 microns, preferably about 1 to 30 microns, and other thicknesses are also possible. Making it too thick tends to result in increased consumption of silver when obtaining high contrast. However, increasing the amount of binder relative to the amount of colorant has the additional advantage of producing low contrast, ie, continuous tone, images with lower amounts of silver. Continuous tone can be obtained to some extent by increasing the amount of silver halide dispersed binder and by using a silver halide emulsion with naturally soft photographic characteristics.

The material having the transferred silver image in the image-receiving layer 2 is then processed in known manner to remove either the silver image layer or the non-silver image layer. The remaining image-receiving layer needs to reveal the colorant contained therein for contrast with the color of the support. Therefore, silver images must be bleached out when they contain white colorants. One of the preferred processing methods is a method of etching and bleaching the silver image area of the image-receiving layer 2.

Figure 1B shows the state in which the silver image area in A has been etched and bleached. Etching bleach solutions include, for example, a solution consisting of cupric chloride, citric acid and hydrogen peroxide, a solution consisting of cupric chloride, potassium bromide, lactic acid and hydrogen peroxide, ferric nitrate, bromide, etc. Liquids consisting of potassium, lactic acid, and hydrogen peroxide are known.

Another processing method is to tan and bleach the silver image area of the image receiving layer 2. Tanning bleaching bleaches the silver and hardens the binder in that area. The non-silver image areas are not hardened and can be dissolved in hot water and removed. For this purpose, it is necessary that the image-receiving layer 2 be not cured at all or only weakly cured. In Figure 1, after tanning and bleaching the silver image area in A,
This shows the state where the non-silver image area has been washed off. A typical tanning bleach solution is a mixed solution of potassium dichromate and hydrochloric acid, and ammonium dichromate, sodium dichromate, etc. are also used. Sulfuric acid, nitric acid, etc. may be used instead of hydrochloric acid.

Another processing method is to perform diffusion transfer development to form a silver image on the image-receiving layer 2, which also serves as tanning development to harden the silver image area, and then wash off the non-image area. This is a method in which the image is treated with an oxidizing agent and a fixing agent (such as a bleach-fixing solution used in ordinary color photography) to remove the image silver, if necessary, before or after the image.

Another preferred processing method is the so-called colloid transfer method, in which the uncured image-receiving layer is pressed onto another sheet and transferred after performing both the above-mentioned diffusion transfer development and tanning development, or after tanning and bleaching. . This method is particularly advantageous since it does not involve the difficult problems of processing colloidal waste liquids as in the etching bleaching and tanning methods described above. In as many as two sheet types, the other sheet may be negative material.

The amount of silver required in the silver halide emulsion layer may be as long as it is necessary for the image-receiving layer 2 to be etched, bleached or hardened, and may be present in very small amounts, for example 5 mmol per square meter, especially 3 mmol (silver nitrate). An image of sufficiently high density can be obtained with a density of 0.51 g/m ² ) or less.

FIG. 2 shows an image-receiving layer 2 containing a black coloring agent such as carbon black on a white opaque support 1, such as baryta paper or polyethylene resin laminated paper containing titanium dioxide, and a silver halide emulsion layer 3 thereon.
This is a mono-sheet photographic material with Of course, the support 1 and the image-receiving layer 2 can also be shaped like a bear as shown in FIG. Figure 2A shows the exposed area of the emulsion layer 3 (in the case of a direct positive silver halide emulsion,
The unexposed area forms chemically developed silver by diffusion transfer development, and at the same time, the unchemically developed silver halide is transferred as a soluble silver complex to the corresponding area of the image-receiving layer 2, where it is transferred due to the presence of physical development nuclei. This indicates that the image has been developed (shaded area). FIG. 2B shows an image formed by the etching bleach method (by etching the image-receiving layer 2, the silver halide emulsion layer thereon is also removed). FIG. 2C shows a state in which an image is formed by the above-described method using the tanning method. In this case, both the image-receiving layer 2 and the emulsion layer 3 need to be unhardened or weakly hardened. hardening
A silver image is added to the black pigment by washing off after DTR development. FIG. 3 shows a monosheet photographic material having a silver halide emulsion layer 3 on a black opaque support 1 and an image receiving layer 2 containing a white colorant thereon. In monosheet materials of this type, it is preferred that the image-receiving layer contains an amount of pigment that allows exposure to visible light. Preferably it is a white pigment such as titanium dioxide. Furthermore, in the monosheet material of FIG. 3, irradiation with radiation that can pass through the image-receiving layer 2 or the support 1, such as X-rays, is also possible. The production of X-ray sensitive materials by the diffusion transfer method is disclosed in US Pat. No. 2,565,378;
It is publicly known and can be referred to, for example, in Japanese Patent Publication No. 3185841 and Japanese Patent Publication No. 48-30892. Photographic materials of the type shown in FIG.
What has been explained in the material of Figure 2 is quoted. Then, a negative image or a positive image can be formed by leaving only the image-receiving layer 2 unhardened or leaving only the emulsion layer 3 unhardened.

By containing luminophore particles in the image-receiving layer 2 or emulsion layer 3, an X-ray sensitive material with a low silver content can be obtained. Of course, the materials shown in FIGS. 1 and 2 can also be irradiated with X-rays, and with such X-ray sensitive materials, increasing the binder content of the image-receiving layer to make it thicker has the advantage of making it possible to obtain more continuous-tone images. A preferred embodiment of the present invention is shown in FIGS. 1 and 2.
This is the type of diagram.

Examples of silver halide photographic materials useful in the practice of the present invention include silver halide black and white photographic materials, photographic materials for printing plates, X-ray photographic materials, microphotographic materials, and photographic materials for copying. This is not limited to these examples.

The silver halide emulsion used in the present invention includes, for example, the composition of silver halide (for example, silver iodobromide, silver bromide, silver chlorobromide, silver chloroiodobromide, etc.), the crystal form of silver halide, and the crystal shape of silver halide. It is not limited by the texture, silver ion concentration in the emulsion, pH of the emulsion, type or amount of hydrophilic binder, etc.

Furthermore, the silver halide emulsion can be chemically sensitized with various sensitizers. For example, sulfur sensitizers (e.g. hypo, thiourea, gelatin containing labile sulfur, etc.), noble metal sensitizers (e.g. gold chloride, gold rhodan, ammonium chloroplatinate, silver nitrate, silver chloride, palladium salts, rhodium salts, iridium salt,
ruthenium salts, etc.), polyalkylene polyamine compounds described in US Pat. No. 2,518,698, iminoamino-methanesulfinic acid described in German Patent No. 1,020,864, ring element sensitizers (e.g., stannous chloride, etc.) are advantageous. used for.

The hydrophilic colloid advantageously used to prepare the photosensitive emulsion in the silver halide photographic light-sensitive material of the present invention can be a binder used in the image-receiving layer as described above.

Silver halide emulsions can also be spectrally sensitized in blue, green, and red. It can be a merocyanine, cyanine dye or other sensitizing dye.

Each component of the silver halide photographic material of the present invention may further contain various additives.

For example, formalin, mucochromic acid, chromium alum, vinyl sulfone compounds, epoxy compounds,
Hardeners such as ethyleneimine compounds, mercapto compounds, anti-capri agents or stabilizers such as tetraazaindene, saponins as surfactants, sodium alkylbenzene sulfonates, sulfosuccinic acid ester salts, alkylaryls described in US Pat. No. 2,600,831. Anionic compounds such as sulfonates and amphoteric compounds as described in U.S. Pat. Wetting agents, mordants such as N-guanyl hydrazone compounds, quaternary onium compounds, tertiary amine compounds, diacetyl cellulose, styrene-perfluoroalkylene sodium maleate copolymers, styrene-maleic anhydride copolymers and P- Antistatic agents such as alkali salts of reactants with aminobenzenesulfonic acid, matting agents such as polymethacrylic esters, polystyrene, colloidal silicon oxide, film property improvers such as acrylic esters, various latexes, glycerin, esp. Gelatin plasticizers such as those disclosed in Japanese Patent Publication No. 43-4939, styrene-maleic acid copolymers, thickeners such as those disclosed in Japanese Patent Publication No. 36-21574, antioxidants, PH regulators, etc. can be used.

The processing liquid used in the diffusion transfer method includes an alkaline substance such as sodium hydroxide, potassium hydroxide, lithium hydroxide, trisodium phosphate, etc., a silver halide solvent such as sodium thiosulfate, ammonium thiocyanate, a cyclic imide compound, Preservatives such as thiosalicylic acid, such as sodium sulfite, thickening agents such as hydroxyethycellulose, carboxymethyl cellulose, antifoggants such as potassium bromide, 1-phenyl-5-mercaptotetrazole, etc., and developing agents if necessary. , for example, hydroquinone, 1-phenyl-3-pyrazolidone, etc., developer modifiers, such as polyoxyalkylene compounds, onium compounds, alkanolamines, etc.

The developer can be contained in the silver halide emulsion layer and/or other hydrophilic colloid layers in water permeable relationship therewith. In this case, as is well known, the processing solution can be an alkaline activating solution that does not substantially contain a developer.

It can be used in the processing method described above by replacing the developer contained in the processing solution or material with a tanning developer. Conditions for tanning, tanning developers, etc. are well known, and can be referred to, for example, Japanese Patent Publication No. 12242/1983. Examples are given below.

Example 1 Gelatin and polyvinyl alcohol (3:2 weight ratio) containing palladium sulfide cores, carbon black, formalin, etc. ) was applied to form an image-receiving layer of 4 g/m ² and dried to prepare an image-receiving material. The carbon black was 1.0 g/m ² and sufficiently masked the whiteness of the support, and the optical reflection density was 1.4.

On the other hand, on the same support as the image-receiving material, an average particle size of 0.3
Ortho-sensitized gelatin emulsion containing micron silver chlorobromide (silver bromide 10 mol%) converted to silver nitrate.
A negative material was prepared by coating and drying at a concentration of 0.3 g/m ² . After imagewise exposure of this negative material, both materials were developed in a conventional manner using the diffusion transfer developer described below.

Sodium hexametaphosphate 0.5g Hydroquinone 12g 1-phenyl-3-pyrazolidone 1g Anhydrous sodium sulfite 75g Sodium thiosulfate 14g Sodium hydroxide 12g Potassium bromide 1.5g Add water to 1.

Next, the image-receiving material was immersed in the known etching bleach solution shown below at 20°C for 90 seconds to remove the image-receiving layer in the area containing the silver image, resulting in a clear, high-density reflection image that was negative for the subject. Ta.

Etch bleach solution A (500ml) Cupric chloride 2.5g Citric acid 2.5g Solution B 3% H ₂ O ₂ aqueous solution 500ml (Mix solutions A and B to make 1) Example 2 For the subject In order to obtain a positive image, a test was conducted using a combination opposite to that of Example 1. That is, an image-receiving material was prepared in the same manner as in Example 1, except that 10 g/m ² of titanium dioxide was used in place of the carbon black on a paper support (optical reflection density 1.7) coated with a polyethylene resin mixed with carbon black. and processed in the same way using the same negative material.

A positive, high-reflection-density image of the subject was obtained.

Example 3 Gelatin (3 g/m 2 ) containing nickel sulfide nuclei, carbon black (0.5 g/m ² ) and a small amount of formalin was placed on the support used in the image-receiving material of Example 1.
An image-receiving material was prepared by providing an image-receiving layer consisting of (g/m ² ).

Carbon black and 0-chlorohydroquinone (1
g/m ² ) containing gelatin subbing layer (approx. 5 microns)
A negative material was prepared by coating and drying an ortho-sensitized silver bromide gelatin emulsion at a concentration of 0.4 g/m ² in terms of silver nitrate. After imagewise exposure of this negative material, both materials were developed in a conventional manner using the developer described below.

Sodium thiosulfate 15g Sodium hydroxide 15g Potassium bromide 1g 1-phenyl-5mercapto-tetrazole
Make 1 with 0.1g water.

Next, the unsilvered areas of the image-receiving material were washed away with hot water at about 50°C, and when dried, a clear image with an optical reflection density of 1.6 was obtained.

Example 4 On the image-receiving material of Example 1, the silver halide emulsion used for the negative material of Example 1 was further coated in the same manner.
It was dried to produce a monosheet material. When this material was subjected to image exposure and then processed according to Example 1, a negative high-density reflection image of the subject was clearly obtained.

Images obtained using the material of the present invention do not contain silver or contain only a small amount of silver, so the DTR method material has the advantage of not having disadvantages such as silver fading caused by silver halide solvents. are doing.

Example 5 The monosheet material of Example 4 was produced in the same manner except that both the image-receiving layer and the emulsion layer were left uncured (or weakly cured), and after transfer development, tanning bleaching and fixing with ammonium thiosulfate were performed. When washed off with warm water, unsilvered areas of the silver halide emulsion layer and image receiving layer were removed, and a positive high density image of the subject was obtained.

Example 6 An image-receiving material was prepared in the same manner as in Example 3 except that formalin was not included in the image-receiving layer, and treated with the same negative material and processing solution. When both materials were pressed together with a roller, the uncured image-receiving layer was A similar image was obtained by transferring to negative material.

[Brief explanation of the drawing]

1 to 3 are illustrative cross-sectional views of the diffusion transfer material of the present invention. A shows the state after diffusion transfer development, and B and C show the state after image formation processing, respectively. DESCRIPTION OF SYMBOLS 1...Support, 2...Colorant-containing image-receiving layer, 3...
...Silver halide emulsion layer.

Claims (1)

[Claims] 1 A material having at least an image-receiving layer containing physical development nuclei for image-wise diffusion transfer and development of a soluble silver complex salt from a silver halide emulsion layer as a silver supply source on an opaque support. The image-receiving layer contains a colorant such as a pigment or dye that does not wash out or disappear during photographic processing, and the colorant has a color that has a sufficiently large contrast or brightness with the color of the opaque support. 1. A silver complex diffusion transfer material comprising: a silver complex salt, and an amount sufficient to substantially mask the color of the opaque support.