JPH0566580B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to an image forming method by silver salt diffusion transfer and a film unit used therein. (Prior Art) Image forming methods by diffusion transfer using silver salts such as silver halides are well known. Specifically, the method includes, for example, treating an imagewise exposed photosensitive silver halide emulsion layer with an alkaline aqueous solution containing a developer and a silver halide solvent, and converting the exposed silver halide grains into silver by the developer. On the other hand, unexposed silver halide grains are converted into a transferable silver complex salt using a silver halide solvent, and this silver complex salt is diffused and transferred into a silver precipitant-containing layer (image-receiving layer) overlaid with the emulsion layer by imbivision. It consists of transferring and then reducing the silver complex with a developer with the help of a silver precipitant to obtain a silver image. When carrying out this method, for example, a light-sensitive element having a light-sensitive silver halide emulsion layer on a support, an image-receiving element having an image-receiving layer containing a silver precipitant on a support, a developer, a halogenated A film unit is used which combines a processing element consisting of a breakable container containing an aqueous activated alkaline solution containing a silver solvent and a thickener. First, the emulsion layer of the light-sensitive element is imagewise exposed, and then the light-sensitive element and the image-receiving element are overlapped so that the emulsion layer and the image-receiving layer of the image-receiving element face each other, while the processing element is destroyed and a viscous alkaline aqueous solution is developed. The image-receiving element is passed between a pair of rollers as shown in FIG. Various proposals have been made to ensure that images formed in this manner can withstand long-term storage. In particular, Tokko Akira
The invention disclosed in No. 58-49861 discloses a method of using a borate compound in a processing composition as a method for suppressing the formation of undesirable crystal bodies or salting-out compositions during storage of additive color images. There is. (Problems to be Solved by the Invention) However, it has been found that when this borate is used in large quantities, it may be difficult to uniformly spread the treatment element. An object of the present invention is to provide a novel image forming method using silver salt diffusion transfer. Another object of the present invention is to provide a method for providing images that are stable for long-term storage. (Means for Solving the Problems) Therefore, the present inventors have found that when at least one of a maleic acid copolymer and an acrylic acid copolymer is present in the image-receiving layer, the dependence on the amount added is small and
As a result of extensive research into a method to extremely strongly suppress the formation of crystals or salting-out compositions during image storage, we have found that:
By using dihydroxypyrimidine containing at least two or more types of thioether groups, the above objects can be achieved, and the generation of the crystals can be
It has been found that this is greatly enhanced when at least one of a maleic acid copolymer and an acrylic acid copolymer is present in the image-receiving layer. That is, in one aspect of the present invention, an image-exposed photosensitive silver halide emulsion layer is developed in the presence of a developer, a silver halide solvent, and an alkali to remove unexposed silver halide in the emulsion layer. In the image forming method by silver salt diffusion transfer, the method includes forming an image on the image receiving layer by transferring at least a part of the complex salt to an image receiving layer containing a silver precipitant, wherein at least a part of the complex salt is a transferable silver complex salt. Containing at least two compounds selected from the following general formulas () and () as a silveride solvent,
and an image-forming method by silver salt diffusion transfer, characterized in that the image-receiving element including the image-receiving layer contains at least one of a maleic acid copolymer and an acrylic acid copolymer. In the formula, R ₁ and R ₅ each represent an alkyl group,
R ₂ and R ₆ each represent a hydrogen atom, an alkyl group or a halogen atom, R ₃ , R ₄ , R ₇ and R ₈ each represent a hydrogen atom or an alkyl group, and m and n each represent 0 to 5. Represents an integer. The alkyl group represented by R ₁ and R ₅ preferably has 1 to 4 carbon atoms, such as a methyl group,
These are ethyl group, isopropyl group, and orbutyl group. Alkyl groups may also include thioether substituents (e.g.
CH ₃ S-), hydroxyl group, carboxy group, amino group, alkoxy group (preferably one or more carbon atoms)
3) etc. may be substituted. The alkyl groups represented by R ₂ and R ₆ preferably have 1 to 5 carbon atoms, and the alkyl groups represented by R ₃ , R ₄ , R ₇ and R ₈ preferably have 1 to 3 carbon atoms.
It is. Each of m and n is preferably 1 or 2. Specific examples of preferred compounds of general formula () or () are shown below.

【formula】

【formula】

【formula】

【formula】

【formula】

【formula】

[Formula] The compound represented by the above general formula () or () is
4211559 and 4211562, and those not described can be easily synthesized by referring to the above-mentioned Japanese Patent Publication No. 4211559 and 4211562. Specific examples of preferred copolymers of maleic acid or acrylic acid are shown below. (a) Styrene-maleic anhydride copolymer (b) Ethylene-maleic anhydride copolymer (c) Methyl vinyl ether-maleic anhydride copolymer (d) Acrylic acid-alkyl acrylate copolymer (e) Acrylic acid -Alkyl methacrylate copolymer (f) Methacrylic acid-alkyl acrylate copolymer (g) Methacrylic acid-alkyl methacrylate copolymer (h) Styrene-maleic acid copolymer (i) Ethylene-maleic acid copolymer The above copolymer is disclosed in Japanese Patent Application No. 58-128224 and Japanese Unexamined Patent Publication No. 59-1989.
-202463, Japanese Patent Publications No. 44-15755, No. 49-26896, US Pat. The present invention will be explained in more detail below. In the image forming method and film unit of the present invention, the developer may be present in the photosensitive element or the processing element. As the developer, a benzene- or naphthalene-based organic compound having a hydroxyl group and/or an amino group in the para or ortho position, such as hydroquinone, tert-butylhydroquinone, p-aminophenol, etc., is used. Furthermore, reductic acid as described in US Pat. No. 3,615,440 and α,β-enediol as described in US Pat. No. 3,730,716 are preferably used. Furthermore, U.S. Patent No. 3,287,125 and
Hydroxylamine developers such as those described in No. 3293034 are particularly preferably used. Further, as a developer, a 1-aryl-3-pyrazolidinone compound described in the invention disclosed in Japanese Patent Publication No. 49-13580 may be used in combination with the above developer. The silver halide solvent of the present invention is preferably present in the processing element. The alkaline agent that makes the PH of the treatment composition alkaline (PH 12 to 14 is preferred) is preferably an alkali metal hydroxide, such as at least one of sodium hydroxide, potassium hydroxide, and lithium hydroxide. The total amount of dihydroxypyrimidine compounds used is preferably 1 to 30 g per 100 g of treatment solution, and the minimum amount of a single compound is preferably 0.05 g per 100 g of treatment solution. The usage ratio of these compounds depends on the grain size, grain shape, halogen composition, and silver amount of the silver halide used, as well as the type and amount of the developer used, and the halogenation of the dihydroxypyrimidine compound used. Although it cannot be determined unambiguously because it depends on silver solubility, in industrial implementation, the minimum ratio of a single dihydroxypyrimidine compound to be used is approximately 1/1 of the total dihydroxypyrimidine compound.
100 (in molar ratio), preferably about 1/10 (in molar ratio)
is even more preferable. The amount of developer used is 5 x 10 ^-3 per 100g of processing solution.
-0.5 mol, preferably 8 x 10 ^-3 - 0.4 mol, more preferably 1 x 10 ^-2 - 0.3 mol. When the processing liquid of the present invention is applied by being distributed as a thin layer between a superimposed photosensitive element and an image receiving element, the processing liquid does not contain a polymeric film forming agent, a thickening agent or a thickening agent. Preferably. Hydroxyethylcellulose and sodium carboxymethylcellulose are particularly useful for this purpose and are included in the processing solution at concentrations effective to provide the appropriate viscosity according to known principles of diffusion transfer photography. The processing solution may further contain other auxiliary agents known in the silver salt diffusion transfer process, such as antifoggants, toning agents, stabilizers, and the like. In particular, the inclusion of oxyethylamino compounds, such as triethanolamine, is useful for increasing the shelf life of processing fluids, as described in US Pat. No. 3,619,185. The processing liquid as described above is preferably stored in a breakable container to serve as a processing element. Any known breakable container and its material can be used; for example, US Pat. No. 3,056,491, US Pat.
No. 3173580, No. 3750907, No. 3833381, No.
It is described in detail in No. 4303750, No. 4303751, etc. At least one of the maleic acid copolymer and the acrylic acid copolymer used in the image receiving element is a binder, i.e., cellulose esters such as cellulose triacetate, cellulose diacetate, cellulose propionate, cellulose acetate butyrate, and polyvinyl acetate. , polyvinyl propionate, polyvinyl chloroacetate, and other polyvinyl esters. In addition, the maleic acid copolymer and/or acrylic acid copolymer used has an average molecular weight of 10,000.
~1,000,000 is preferable, and the usage amount is 1 m ² of image receiving layer.
0.1g to 20g per serving is preferable. Furthermore, 1 to 10 g is most preferable. In the present invention, the total copolymer/binder ratio of at least one of the maleic acid copolymer and the acrylic acid copolymer used in the image receiving element is 1/9 to 1/9.
3/2 is preferable, and 3/7 to 1/1 is more preferable. Although at least one of the maleic acid copolymer and acrylic acid copolymer is preferably contained in the neutralization layer, a portion of all the copolymers may be contained in the neutralization timing layer. The maleic acid copolymer and acrylic acid copolymer used in the present invention are effective as neutralizing agents for alkaline agents that permeate. It is also preferred to provide a layer (timing layer) of a suitable cellulose ester, such as cellulose diacetate, between the intermediate layer and the acid copolymer layer. Furthermore, the image-receiving element of the present invention includes a support carrying an image-receiving layer containing a silver precipitant, such as baryta paper, cellulose triacetate or polyesters. Such image-receiving elements can be prepared by coating an optionally subbed support with a coating solution of a suitable cellulose ester, such as cellulose diacetate, preferably dispersed with a silver precipitating agent. The obtained cellulose ester layer is subjected to alkaline hydrolysis to convert at least a portion of the cellulose ester in the depth direction into cellulose. In a particularly useful embodiment, the unhydrolyzed portion of the cellulose ester layer containing the silver precipitant and/or the underlying unhydrolyzed cellulose ester, such as cellulose diacetate, is the silver transfer agent. the color of the image,
Contains one or more mercapto compounds suitable for improving stability or other photographic properties. Such mercapto compounds are utilized during imbibition by diffusing from the position where they are initially placed. This type of receiver element is described in US Pat. No. 3,607,269. Examples of suitable silver precipitants include heavy metals such as iron, lead, zinc, nickel, cadmium, tin, chromium, copper, cobalt, especially noble metals such as gold,
There are silver, platinum and palladium. Other useful silver precipitants are sulfides and selenides of heavy metals, especially sulfides of mercury, copper, aluminium, zinc, cadmium, cobalt, nickel, silver, lead, antimony, bismuth, cerium and magnesium, and sulfides of lead, zinc. , antimony and nickel selenide. The function of materials such as silver precipitants in silver salt diffusion transfer processes is described, for example, in US Pat. No. 2,774,667. Furthermore, it is preferable to provide an intermediate layer between the image-receiving layer and the layer containing a toning agent or stabilizer. Preferred materials for the intermediate layer include gum arabic, polyvinyl alcohol, and polyacrylamide. Further, it is preferable to provide a peeling layer on the surface of the image-receiving layer in order to prevent the treatment liquid from adhering to the surface of the image-receiving layer during peeling after spreading the treatment liquid. Preferred materials for such a release layer include gum arabic,
In addition to hydroxyethylcellulose, methylcellulose, polyvinyl alcohol, polyacrylamide, and sodium alginate, US Patent 3772024
No. 3,820,999 and British Patent No. 1,360,653. In particular embodiments of the invention, image-receiving layers can be incorporated into the photosensitive elements described below. For example, on a polyethylene terephthalate sheet, an image-receiving layer containing a silver precipitant, a light-reflecting layer containing a white pigment such as titanium dioxide, a light-shielding layer containing a light-absorbing substance such as carbon black, and a photosensitive silver halide A preferred example is one provided with an emulsion layer. In such an embodiment, the light-reflecting layer shields the layer behind the photosensitive silver halide emulsion layer after the diffusion transfer process, so that the image formed on the image-receiving layer can be observed through the polyethylene terephthalate sheet. can do. Further, in the present invention, a photosensitive element obtained by coating a photosensitive silver halide emulsion on a support is preferred. In the photosensitive silver halide emulsion used in the present invention, any one of silver bromide, silver iodobromide, silver iodochlorobromide, silver chlorobromide, and silver chloride may be used as the silver halide. Preferred silver halides are silver iodobromide or silver iodochlorobromide containing 10 mol % or less of silver iodide. Particularly preferred is silver iodobromide containing from 3 mol % to 10 mol % silver iodide. Average grain size of silver halide grains in a light-sensitive emulsion (grain diameter for spherical or approximately spherical grains, edge length for cubic grains,
(expressed as an average based on the projected area) is not particularly limited, but is preferably 3μ or less, more preferably 1.5μ or less, and particularly preferably 0.8 to 1.2μ. The particle size distribution may be narrow or wide. The silver halide grains in the light-sensitive emulsion are cubic,
It may have an equiaxed crystal form such as an octahedron, it may have an irregular crystal form such as a spherical shape or a plate shape, or it may have a composite form of these crystal forms. It may also consist of a mixture of particles of various crystalline forms. The interior and surface layers of the silver halide grains may be composed of different phases, or may be composed of a uniform phase. Further, the particles may be particles in which the latent image is mainly formed on the surface, or may be particles in which the latent image is mainly formed inside the particle. Particles in which latent images are mainly formed on the surface are preferred. The thickness of the photosensitive emulsion layer is 0.5~8.0μ, especially 0.6~
6.0μ, and the coating amount of silver halide grains is 0.1~
3 g/m ² , preferably 0.2 to 1.5 g/m ² . The light-sensitive emulsion is prepared by a method commonly used for silver halide photographic emulsions, chemical sensitization and spectral sensitization are performed as necessary, and antifoggants, antifoggants, etc. are added to the emulsion.
It may contain stabilizers, hardeners, coating aids, antistatic agents, and the like. Also, a vehicle such as gelatin is used in the emulsion. Exposure to obtain a photographic image may be carried out using a conventional method. That is, any of the various known light sources can be used, such as natural light (sunlight), tungsten electric lamps, fluorescent lamps, mercury lamps, xenon arc lamps, carbon arc lamps, xenon flash lamps, cathode ray tube flying spots, and the like. Exposure times include not only exposure times of 1/1000 seconds to 1 second that are normally used with cameras, but also exposures shorter than 1/1000 seconds, such as exposures of 1/10 ⁴ to 1/10 ⁶ seconds using xenon flash lamps and cathode ray tubes. or exposures longer than 1 second can be used. If necessary, the spectral composition of the light used for exposure can be adjusted using a color filter. Laser light can also be used for exposure. Alternatively, exposure may be performed using light emitted from a phosphor excited by electron beams, X-rays, γ-rays, α-rays, or the like. The arrangement and combination method of each element to form a film unit by combining the photosensitive element, image receiving element, and processing element as described above can be found in, for example, Neblette's Handbook of Photography and Reprography.
PHOTOGRAPHY AND REPROGRAPHY),
7th Edition, pages 282-285, and particularly preferred embodiments are detailed in US Pat. No. 3,350,991, which may be referred to. (Effect of the invention) The dihydroxypyrimidine compound represented by formula () or () used in the present invention is disclosed in U.S. Pat. No. 4,126,459, U.S. Pat.
4211562, which states that the dihydroxypyrimidine compounds can be used alone or in mixtures with each other or with other silver halide solvents to obtain photographs with appropriate maximum density and sensitivity. be. On the other hand, when an image print is stored for a long period of time, crystals are generated on the surface of the print. It has been found that the generation is promoted by the maleic acid copolymer or acrylic acid copolymer constituting the image print, and that crystals are generated when the dihydroxypyrimidine compound is used alone. However, it has been unexpectedly discovered that by using two or more specific compounds represented by formula () or () in a specific ratio, the formation of the above-mentioned crystals does not substantially occur. Ta. In this respect, it is clear that the present invention is in no way analogous to the aforementioned US Pat. No. 4,126,459. Thus, according to the present invention, when using an image-receiving sheet containing at least one of a maleic acid copolymer and an acrylic acid copolymer, by using two or more dihydroxypyrimidine compounds in combination, the long-term preservation of images, especially, Prevention of crystallization on the image surface can be achieved. (Examples) Hereinafter, the present invention will be explained in more detail based on Examples, but the present invention is not limited to these Examples in any way. Example 1 Photosensitive sheet Silver halide grains were formed by a single-jet method, physically ripened by a conventional method, desalted, and chemically ripened to form a silver iodobromide emulsion (with an iodo content of
5.5 mol%) was obtained. The average diameter of the silver halide grains contained in this emulsion was 0.9 microns. 0.65 mol of silver halide was contained in 1 kg of this emulsion. Each 1 kg of this emulsion was collected in a pot and dissolved in a constant temperature bath at 50°C. Ortho-sensitizing dye 3-{5-chloro-
2-[2-ethyl-3-(3-ethyl-2-benzothiazolinylidene)propenyl]-3-benzoxazolio}propane-sulfonate, panchromatic sensitizing dye 4-{2-[(3-ethylbenzo thiazolin-2-ylidene)-2-methyl-1-propenyl]-3-benzothiazolio}butane-sulfonate and 4-hydroxy-6-methyl-1,3,
1% by weight aqueous solution of 3a,7-tetrazaindene10
ml, 10 ml of a 1% by weight aqueous solution of 2-hydroxy-4,6-dichlorotriazine sodium salt, 10 ml of a 1% by weight aqueous solution of sodium dodecylbenzenesulfonate, and 10 ml of a 0.1% by weight methanol solution of lipoic acid.
were added and mixed and stirred at 40°C. This finished emulsion was applied to an undercoated polyethylene terephthalate film base containing titanium dioxide to a dry film thickness of 3.
A sample was obtained by applying it to a micron thickness and drying it. At the same time, polymethyl methacrylate latex (average size 3.5 μm) was added to the gelatin aqueous solution and coated to a dry film thickness of 1 μm.
The amount of silver coated was 0.5 g/m ² . Image-receiving sheet: 18 g of cellulose acetate (degree of acetylation 54%) as shown in the following table on polyethylene laminated paper.
A solution prepared by dissolving 12 g of styrene-maleic anhydride copolymer or 12 g of acrylic acid-alkyl acrylate copolymer in 270 ml of acetone and 30 ml of methanol was applied to a thickness of 54 ml/m ² and dried. On top of this
0.05 g/m ² A 10% cellulose acetate acetone solution of 3,6-diphenyl-1,4-dimercapto-3H,6H-2,3a,5,6a-tetrazapentalene was prepared with a dry film thickness of 10 g/m ^{2 .} I applied it to make it look like this.
Furthermore, on top of this, add a 5% aqueous solution of polyacrylamide, a dimethylol urea (5%) aqueous solution and acetic acid (50%).
were added and mixed at concentrations of 5%, 1, and 25%, respectively, and 25
It was applied at a coating thickness of ml/m ² . Furthermore, on top of this, 3%
A solution in which palladium sulfide was finely dispersed was applied to an acetone/methanol (9/1) solution of cellulose acetate. This coating solution contained 1-phenyl-5-mercaptoimidazole in a coating amount of 1.25×10 ⁻⁶ mol/m ² . Dry film thickness is 0.8μm
It was hot. Apply the following alkaline solution to this application.
It was applied at a rate of ml/m ² , washed with water and dried to prepare an image receiving sheet. The above palladium sulfide dispersion was prepared by adding a 7 x 10 ^-3 mol sodium sulfide methanol solution and a 7 x 10 ^-3 mol sodium palladium chloride methanol solution to a 5.3% acetone/methanol (9/1) mixed solution of cellulose acetate. Add it and stir well. Treatment liquid Potassium hydroxide (85%) 260g Titanium dioxide 3g Hydroxyethyl cellulose 70g Zinc oxide 10g N,N-bismethoxyethylhydroxylamine 50g Triethanolamine 7g Tetrahydropyrimidinethione 0.4g 2,4-dimercaptopyrimidine 0.35g 6-n Propylthiouracil 0.35g The following compound was added to the above processing solution, and water was further added to make a total amount of 2 kg.The processing solution was spread between the photosensitive sheet and the image-receiving sheet, and after 5 minutes had elapsed. Peeled off. The amount of these additions depends on the image sensitivity, gradation,
The maximum density, minimum density and completion time were determined to be almost the same as in Example 1 of Table 1. The obtained image was left at room temperature for one week, and the surface condition of the image at that time was observed.

【table】

[Table] From Table 1, if there is a vinegar copolymer layer, crystals will occur on the print surface, but by using a combination of multiple dihydroxypyrimidine compounds of the present invention, even if the acid copolymer is present, crystals will not form on the print surface. It can be seen that no crystals are generated.

Claims (1)

[Scope of Claims] 1. An imagewise exposed photosensitive silver halide emulsion layer is developed in the presence of a developer, a silver halide solvent and an alkali to remove at least a portion of the unexposed silver halide in the emulsion layer. In an image forming method by silver salt diffusion transfer, which includes using a transferable silver complex salt and transferring at least a part of the complex salt to an image receiving layer containing a silver precipitant to form an image on the image receiving layer, the silver halide solvent is At least one of a maleic acid copolymer and an acrylic acid copolymer is added to the image receiving element containing at least two compounds selected from the following general formulas () and () and including the image receiving layer. An image forming method by silver salt diffusion transfer, characterized by comprising: [Formula] [Formula] In the formula, R ₁ and R ₅ each represent an alkyl group,
R ₂ and R ₆ each represent a hydrogen atom, an alkyl group or a halogen atom, R ₃ , R ₄ , R ₇ and R ₈ each represent a hydrogen atom or an alkyl group, and m and n each represent 0 to 5. Represents an integer.