JPH0465374B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to an image receiving element used in a silver salt diffusion transfer process, and more particularly, to an image receiving element used in a silver salt diffusion transfer process that forms images with improved tone. Regarding elements.

(Prior Art) The principle of the silver salt diffusion transfer method is described in US Pat. No. 2,352,014 and the like.

In the silver salt diffusion transfer method, silver complex salts are transferred by diffusion from a light-sensitive silver halide emulsion layer to an image-receiving layer where they are converted into a silver image by the action of physical development nuclei. To this end, the imagewise exposed silver halide emulsion layer is developed by a processing solution in the presence of a developing agent and a silver ion complexing agent. The silver halide in the exposed parts of the negative emulsion layer is developed to silver so that it can no longer be dissolved and therefore cannot be diffused. The silver halide in the unexposed portions of such a negative emulsion layer is converted into a soluble silver complex salt by a silver halide solvent acting as a silver complexing agent. The soluble silver complex salt is transferred by diffusion to an image-receiving layer that is brought into effective contact with an adjacent image-receiving layer or emulsion layer, and is then transferred to the image-receiving layer in the presence of physical development nuclei that catalyze the reduction of the transferred complexed silver ions. A positive silver image or a silver-containing image is formed therein. When using a direct positive silver halide emulsion layer instead of a negative silver halide emulsion layer, the silver halide in the unexposed areas is developed and the silver halide in the exposed areas is transferred as described above. A negative silver image is formed in the image-receiving layer. The silver salt dissolved by effective contact can be transferred by diffusion from the emulsion layer to the image-receiving layer, if desired through an intermediate layer provided between the emulsion layer and this image-receiving layer. Whenever such an intermediate layer is present, it must not interfere with the diffusion of the silver salt.

The silver salt diffusion transfer method has a wide range of possible applications.

JP-A-50-34523 describes that continuous tone images can be obtained by modifying the silver halide emulsion layer.

In the above-mentioned silver salt diffusion transfer method, it is important to obtain a pure black to blue-black silver image in the image-receiving layer. Particularly in continuous tone images, it is extremely important quality to obtain a neutral gray transferred silver image from a low density area to a high density area. However, it is known that in such silver salt diffusion transfer methods, the silver image is generally not black but exhibits brown or other unacceptable colors. Therefore, in order to eliminate these drawbacks of the silver salt diffusion transfer method,
Toning agents are used. Various color toning agents are known. A typical example is 1-phenyl-
Mention may be made of 5-mercaptotetrazole. However, the use of known toning agents is largely insufficient, and it is difficult to obtain neutral gray silver images from low to high density areas, especially in continuous tone images.

The color tone of the transferred silver image also changes depending on the type of physical development nucleus. Common physical development nuclei include silver,
Examples include heavy metals such as gold, platinum, palladium, copper, cadmium, lead, cobalt, and nickel, or their sulfides and selenides. These physical development nuclear materials can be prepared by reducing the corresponding metal ions to create a metal colloid dispersion, or by mixing a metal ion solution with a soluble sulfide or selenide solution to form water-insoluble metal sulfides or metal selenides. obtained by making a colloidal dispersion of Furthermore, it is known that even if the metals, metal sulfides, or selenides are of the same type, physical development nuclei having different physical properties such as shape depending on the method of preparation affect the color tone of the transferred silver image.

However, depending on the selection of physical development nuclei, the high-density area may be neutral, but the low-density area may be brownish-brown, or if a neutral color that is satisfactory to some extent is obtained, the density may decrease significantly. However, I have not been able to obtain satisfactory results.

OBJECTS OF THE INVENTION It is an object of the present invention to provide an image receiving element that provides a desirable pure black image.

(Means for Solving the Problems) The above-mentioned object of the present invention is to apply at least one type of insoluble heavy metal sulfide, which is composed of two or more types of insoluble heavy metal sulfides and which contains at least one type of heavy metal, as physical development nuclei. This was achieved by an image-receiving element characterized by containing physical development nuclei having a structure to which an insoluble heavy metal sulfide of a different type than the former containing different types of heavy metals is attached.

As a result of intensive research into the color tone improvement of silver salt diffusion transfer images based on the shape and structure of physical development nuclei, the present inventors found that the mixing state or association state of multiple types of physical development nucleus substances is important for color tone improvement. It has been found that a structure in which at least one of the plurality of physical development nucleus substances adheres to and aggregates on the surface of the remaining physical development nucleus substances is essential.

It has been known for some time that mixtures of insoluble heavy metal sulfides can be used as physical development nuclei. In this case, a method is used in which a solution containing a plurality of metal ions and a soluble sulfide solution are mixed to obtain an insoluble mixed metal sulfide colloidal dispersion.

The physical development core material prepared by the above-mentioned conventional method is either a mixture of multiple insoluble metal sulfides forming an aggregated state, or a mixed state of a single insoluble sulfide of each metal. It is believed that this method can selectively form a structure in which one type of physical development nuclear material (not necessarily one type) adheres to and aggregates on the surface of a different type of physical development nuclear material. It's hard to imagine. On the other hand, a first metal ion solution containing at least one metal ion and a soluble sulfide solution containing an excessive amount of soluble sulfide with respect to all the metal ions contained therein are mixed, and once the insoluble An insoluble mixed metal sulfide colloidal dispersion obtained by mixing a second metal ion solution different from the first metal ion solution containing at least one kind of metal ion into the generated metal sulfide colloidal dispersion, or A colloidal dispersion of an insoluble metal sulfide is produced by mixing the first metal ion solution and a soluble sulfide solution containing an amount of soluble sulfide equivalent to all metal ions contained therein; The insoluble mixed metal sulfide colloidal dispersion obtained by mixing the second metal ion solution and the soluble sulfide solution in the presence of insoluble metal sulfide produced by the metal ions contained in the first metal ion solution It seems possible to explain that the insoluble metal sulfide generated by the metal ions contained in the second metal ion solution adheres to the surface of the object and forms an aggregated structure. This is because insoluble metal sulfide has already been generated by the metal ions contained in the first metal ion solution, and is contained in the second metal ion solution with the surface of the insoluble metal sulfide particle as a nucleus. This is because it is highly conceivable that the precipitation and growth of insoluble metal sulfides due to the metal ions present in the metal sulfides occur selectively.

The physical development nuclear material prepared in this way is
It is different from a physical development nucleus material prepared by a conventional method with the same composition, or from a physical development nucleus material obtained by separately preparing a single insoluble metal sulfide colloidal dispersion of each metal contained and then mixing them. Only the receiving elements containing the physical development nuclei of this invention were capable of forming neutral gray continuous tone silver images without loss of maximum density.

Preferred examples of metals contained in the first metal ion solution used in the physical development nuclei used in the image receiving element of the present invention include nickel and cobalt, but other heavy metals such as zinc, tin, iron, Palladium or the like may also be used. Further, two or more of these metals may be used in combination, or metals contained in the second metal ion solution may be combined. A preferable example of the metal contained in the second metal ion solution is silver, but copper can also be used. Moreover, you may use these together. Furthermore, silver or copper can be used in combination with one or more of the other heavy metals, such as those listed in the first metal ion solution. The molar ratio of the metal contained in the first metal ion solution to the metal contained in the second metal ion solution may be between 1:9 and 9:1, preferably between 1:1 and 4:1. It's between. Hydrophilic colloid substances used for physical development nucleus preparation include:
Commonly used hydrophilic colloid substances such as gelatin, carboxymethyl cellulose, hydroxyethyl cellulose, polyvinyl alcohol, polyacrylamide, acrylamide-vinylimidazole copolymer, etc. can be used alone or in combination.

Preferred embodiments of the method for preparing physical development nuclei used in the image-receiving layer of the image-receiving element according to the present invention have been described in detail above, but the physical development nuclei used in the present invention are limited to the physical development nuclei obtained by the above-mentioned preparation method. Rather than selectively forming a structure in which at least one type of insoluble metal sulfide caused by the metal contained in the second metal ion solution adheres to and aggregates on the outermost surface of an insoluble metal sulfide of a different type, All physical development nuclei obtained by a preparation method that can be formed, such as a combination or repetition of the above preparation methods, can be included. The physical development nuclei contained in the image-receiving layer are in an amount ranging from about 2.times.10.sup. ^-6 to about ^{5.times.10.sup.} -5 mol/ ^m.sup.2 as a total amount of insoluble metal sulfide.

Binders for the image-receiving layer include gelatin, phthalated gelatin, acylated gelatin, phenylcarbamylated gelatin, carboxymethyl cellulose, hydroxyethyl cellulose, sodium alginate, polyvinyl alcohol, partially saponified polyvinyl alcohol, polyvinyl alcohol and maleic anhydride. Heat processed products with copolymers (e.g. styrene-maleic anhydride, ethylene maleic anhydride, etc.), polyacrylamide, poly-N-vinylpyrrolidone, latexes (e.g. polyacrylic ester, polymethacrylic ester, Water-soluble polymer compounds such as polystyrene, polybutadiene, etc. alone or in combination can be used.

The image-receiving layer can be hardened with a suitable hardening agent. Specific examples of hardening agents include formaldehyde,
Aldehyde compounds such as glutaraldehyde, ketone compounds such as diacetyl and cyclopentanedione, bis(2-chloroethylurea)-2
-Hydroxy-4,6-dichloro-1,3,5 triazine, compounds with reactive halogens as described in U.S. Pat. No. 3,288,775, divinyl sulfone, compounds with reactive olefins as in U.S. Pat. No. 3,635,718. , N-methylol compounds as described in U.S. Pat. No. 2,732,316, U.S. Pat.
Isocyanates as described in US Pat. No. 3,017,280, aziridine compounds as described in US Pat. No. 2,983,611, carbodiimide compounds as described in US Pat. No. 3,100,704, US Pat. No. 3,091,537
Epoxy compounds as described in No. 1, halogenocarboxaldehydes such as mucochloric acid, dioxane derivatives such as dihydroxydioxane, inorganic hardening agents such as chromium alum, potassium alum, and zirconium sulfate, etc., and one or more of these may be used. Can be used in combination.

The image-receiving layer has a surfactant surface (for example, natural surfactants such as saponin, nonionic surfactants such as alkylene oxide, glycerin, and glycidol, higher alkylamines, quaternary ammonium salts, pyridine, and other heterocycles). , cationic surfactants such as sulfoniums, carboxylic acids, sulfonic acids, phosphoric acids, sulfuric acid ester groups, anionic surfactants containing acidic groups such as phosphoric ester groups, amino acids, aminosulfonic acids, sulfuric acid or phosphoric acid esters of amino alcohols. amphoteric surfactants such as fluorine-containing anions and amphoteric surfactants), matting agents, fluorescent dyes, discoloration inhibitors, color toning agents (such as 1-phenyl-5
-Mercaptotetrazole, other color toning agents described in Focal Press Publishing, Photographic Silver Halide Diffusion Process, page 61), developing agents (e.g., hydroquinone and its derivatives, 1-phenyl-3-pyrazolidone and its derivatives) etc.), silver halide solvents (eg, sodium thiosulfate, ammonium thiosulfate, sodium thiocyanate, potassium thiocyanate, etc.), and the like. Further, an over layer may be provided on the image receiving layer, a neutralizing layer below the image receiving layer, and a subbing layer for improving adhesion to the support.

The silver halide emulsion used in the photosensitive layer of the photosensitive material for silver salt diffusion transfer according to the present invention is an emulsion commonly used for diffusion transfer, and there are no strict regulations on the composition of this emulsion. may be capable of developing and diffusing in the exposed and non-exposed areas at the speed required for the diffusion transfer method, respectively.
Silver bromide, silver iodide, silver chloride, silver chlorobromide, silver iodobromide,
Mention may be made of silver chloroiodide, silver chloroiodobromide and mixtures thereof. As mentioned above, the present invention
For example, as described in JP-A-50-34523, silver chloride iodide or silver chloroiodobromide silver halide with a high content of silver chloride is used, and a polymer binder is added in a high ratio to the silver halide in an emulsion. layer (and layer above it)
It is suitable as an image-receiving element for forming continuous tone images using photosensitive materials used in . However, the material is not particularly limited to such photosensitive materials. Silver halide emulsions can be sensitized in a variety of ways when they are manufactured or coated. It may be chemically sensitized by methods well known in the art, for example with sodium thiosulfate, alkylthioureas, or with gold compounds such as rhodan gold, gold chloride, or a combination of both. good. In addition, commonly used spectral sensitization can be performed.

As the binder for the photosensitive layer, a polymeric substance commonly used in the production of silver halide emulsions, such as the binder described in the image-receiving layer, can be used. The photosensitive layer can also be hardened using a suitable hardening agent as described for the image-receiving layer. Furthermore, the photosensitive layer contains additives generally used in silver halide photosensitive materials, such as surfactants, antifoggants, matting agents, fluorescent dyes, and developing agents (e.g., hydroquinone and its derivatives, 1-phenyl-3-pyrazolidone). and its derivatives). Furthermore, in addition to the photosensitive layer, auxiliary layers such as an undercoat layer, an intermediate layer, a protective layer, and a release layer may be provided as necessary.

The support for the silver salt diffusion transfer photosensitive material and image-receiving material according to the present invention is any commonly used support. These include paper, glass, films such as cellulose acetate film, polyvinyl acetal film, polystyrene film, polyethylene phthalate film, etc., metal supports coated on both sides with paper, paper coated on one or both sides with alpha-olefin polymers such as polyethylene. Supports can also be used.

In general, the silver salt diffusion transfer method is divided into the so-called "mono-sheet method" in which the light-sensitive material and the image-receiving material are formed on the same support, and the so-called "mono-sheet method" in which the light-sensitive material and the image-receiving material are formed on separate supports. There is a so-called "two-sheet" method, in which two materials are stacked and pressed together with a roller to perform diffusion transfer and then peeled off, and the present invention is applicable to either of these methods.

The treatment liquid for silver salt diffusion transfer in the present invention can have a composition of a usual silver salt diffusion transfer treatment liquid.
That is, developing agents for developing exposed silver halide, such as hydroquinone and its derivatives, 1-phenyl-3-pyrazolidone and its derivatives, solvents for undeveloped silver halide, such as sodium thiosulfate, ammonium thiosulfate,
Sodium thiocyanate, potassium thiocyanate, etc.
Sodium sulfite as a preservative, potassium bromide as a development inhibitor, additives such as 1-phenyl-5-mercaptotetrazole as a color toning agent, alkaline substances such as sodium hydroxide, potassium hydroxide, lithium hydroxide, and tertiary phosphoric acid. It may contain thickening agents such as sodium, carboxymethyl cellulose, hydroxyethyl cellulose, and the like.

EXAMPLES The present invention will be explained below with reference to Examples, but the present invention is not limited in any way.

Example 1 Liquid A: 90 ml deionized water 10 g geline Liquid B: 0.05 mol/aqueous solution of Na ₂ S 35 ml Liquid C: 0.05 mol/aqueous solution of Ni(NO ₃ ) ₂ 22.5 ml Liquid D: 0.1 mol/aqueous solution of AgNO ₃ 12.5ml Pre-mix liquids C and D, and add liquids A and B.
Add physical development nuclear solution A to the mixture while stirring well.
I made it.

Add liquid C to a mixture of 64 ml of liquid A and 22.5 ml of liquid B with good stirring, and separately add liquid D to the remaining mixture of liquid A and liquid B while stirring well. Physical development nuclear solution B was prepared by mixing with the added mixed solution.

Liquids A and C were mixed in advance, liquid B was added with good stirring, and then, 5 minutes later, liquid D was added with good stirring to prepare a physical development nuclear solution C.

0.7 g/m ² on one side of a 90 g/m ² paper support coated on both sides with polyethylene previously treated with corona discharge.
A gelatin image-receiving layer containing the above-mentioned physical development nuclear solutions A, B, and C was prepared with a hydrophilic colloid dry weight of 2 g/ ^m2
Image-receiving materials A, B (comparison), and C (invention) were prepared by providing the following conditions.

On the other hand, on the same paper support as the image-receiving material, carbon black and 1
A gelatin subbing layer (gelatin 3 g/m ² ) containing hydroquinone (g/m ² ) and 1-phenyl-4-methyl-3-pyrazolidone (0.3 g/m ² ) is applied on top of the gelatin subbing layer (gelatin 3 g/m 2 ). A gelatin silver halide emulsion layer (silver nitrate) containing 1.8 g/m ² (calculated as silver nitrate) of 8 mol % of silver oxide, 1 mol % of silver iodide), and further containing 0.15 g/m ² of hydroquino, etc. :gelatin=1:4) and protective layer (gelatin 1.3g/
m ² ) was provided to produce a photosensitive material.

The emulsion side of the light-sensitive material exposed for sensitometry and the image-receiving side of the image-receiving material are superimposed and passed through a normal processor containing the following developing solution 1, and 30 seconds after exiting the squeegee roller, both materials are separated. I peeled it off.

The processing liquid temperature was 20°C.

<Diffusion transfer developer> Water 800ml Anhydrous sodium sulfite 50g Sodium hydroxide 4g Sodium thiosulfate (pentahydrate) 20g N-methylaminoethanol 15g Hydroquinone 11g 1-phenyl-3-pyrazolidone 1g 1-phenyl-5-mercaptotetrazole 50mg Potassium bromide 1g Add water 1 Comparative image-receiving materials A and B produced silver images with sufficient gradation to reproduce continuous-tone originals, but the images were significantly different from low to medium density areas. It was reddish brown. On image-receiving material C, a silver image was formed with a gradation similar to that of the comparative sample, and the image had a good neutral gray tone.

Example 2 A photosensitive material was prepared in exactly the same manner as in Example 1 except that catechol was used instead of hydroquinone in the undercoat layer. Thereafter, silver images were formed on three types of image-receiving materials in the same manner as in Example 1. Comparative image-receiving material A had improved gradation and color tone than Example 1, but the color tone was still not satisfactory. Comparative image-receiving material B had improved color tone compared to Example 1, but the gradation was not as improved as image-receiving material A, and the maximum density was also lower. Image-receiving material C of the invention was a neutral gray silver image with good continuous gradation and even sharpness.

Example 3 Example 1 was repeated. However, when preparing physical development nuclei for the image-receiving material, liquid C is mixed with cobalt nitrate.
An image receiving material was prepared using 22.5 ml of 0.05 mol/aqueous solution instead. As in Example 1, only the image-receiving material C of the present invention recorded a good neutral gray image.

Example 4 Example 2 was repeated. However, as in Example 3, cobalt nitrate was used as liquid C when preparing physical development nuclei for the image-receiving material. As in Example 2, only the image-receiving material C of the present invention recorded an image of good continuous gradation and even more neutral gray.

Claims (1)

[Claims] 1. In an image-receiving element in which at least one image-receiving layer having physical development nuclei is coated on a support in the silver salt diffusion transfer method, the physical development nuclei are composed of two or more types of insoluble heavy metal sulfides, and at least one type of heavy metal is On the surface of insoluble heavy metal sulfides containing
An image receiving element characterized in that it contains physical development nuclei having a structure to which an insoluble heavy metal sulfide different from the former containing at least one type of heavy metal is attached.