JPH087424B2 - Image forming method by silver salt diffusion transfer - Google Patents

Description

TECHNICAL FIELD The present invention relates to an image forming method by silver salt diffusion transfer and a film unit used therefor.

(Prior Art) An image forming method by diffusion transfer using a silver salt such as silver halide is well known. Explaining the various methods in detail,
For example, a photosensitive silver halide emulsion layer which has been imagewise exposed is provided with a developer, a silver halide solvent and a film forming agent (thickener).
Treated with an alkaline aqueous solution containing, to reduce the exposed silver halide grains to silver with a developer, while the unexposed silver halide grains are converted to a transferable silver complex salt with a silver halide solvent. The silver precipitating agent-containing layer (image receiving layer) superposed on the emulsion layer is diffused and transferred by the invisibility, where a silver complex salt is reduced with a developer with the aid of a silver precipitating agent to obtain a silver image. .

In carrying out this method, for example, a light-sensitive element having a light-sensitive silver halide emulsion layer usually provided on a support, an image-receiving element and a developer having an image-receiving layer containing a silver precipitating agent on a support, a halogenated compound are used. A film unit is used which is a combination of processing elements consisting of a destructible container containing an aqueous alkali solution containing a silver solvent and a film forming agent. First, the emulsion layer of the light-sensitive element is imagewise exposed, and then the light-sensitive element and the image-receiving element are superposed so that the emulsion layer and the image-receiving layer of the image-receiving element face each other, while the processing element is destroyed to develop a viscous alkaline aqueous solution. As described above, a print having a desired image formed on the image-receiving layer can be obtained by allowing the image-receiving element to pass through a pair of rollers, leaving it for a predetermined time, and then peeling off the image-receiving element.

(Problems to be Solved by the Invention) However, it has been difficult to bring the color tone of the image obtained by the silver salt diffusion transfer method close to that of the conventional method. That is, the morphology of the silver image obtained by the silver salt diffusion transfer method is spherical, which is different from the filament shape of the conventional chemical development method. As a result, the color tone of the silver image becomes dark brown, so a halftone black color is created by the color tone agent.

However, the silver image obtained by using the toning agent is formed by gathering spherical silver, which is quite different in shape from filament silver. For this reason, although it is a halftone black color, it is slightly chilled, and if the amount of the toning agent is reduced to reduce the degree thereof, the reddishness increases and it becomes reddish purple, which is not preferable. Thus, it is difficult to obtain a yellowish tint by adjusting the amount of the color toning agent.

(Object of the Invention) An object of the present invention is to provide a novel image forming method by silver salt diffusion transfer.

Another object of the present invention is to provide a method for increasing the yellowness by bringing the color tone of the formed image close to that of the conventional method.

(Means for Solving the Problems) The above-mentioned object is to develop a photosensitive element containing an image-exposed photosensitive silver halide emulsion layer in the presence of a silver halide solvent using an alkali processing composition, A silver salt containing at least a part of unexposed silver halide in the emulsion layer as a transferable silver complex salt, and transferring at least a part of the complex salt to a silver precipitating agent-containing image receiving layer to form an image on the image receiving layer. In the image forming method by diffusion transfer, it could be achieved by incorporating carbon black into the photosensitive element.

When the carbon black was contained in the light-sensitive element, the color tone of the silver image was unexpectedly yellowed and a deep color tone was obtained.

As the carbon black of the present invention, well-known ones are generally used, for example, black fine powder obtained by incomplete combustion or thermal decomposition of natural gas or liquid hydrocarbon, the main component of which is 1 to 600 mμ as colloid. It is a carbon with an average particle diameter of and a crystal structure similar to that of graphite.

The dispersion method is generally a mechanical dispersion method, but in addition to water, a dispersion method using a protective colloid agent such as bittern or gelatin is also used.

Although the surface of the carbon black is used as it is, it is also effective to subject it to an oxidation treatment with hypochlorite or the like, or a treatment such as graft polymerization.

 It is preferably contained in the uppermost protective layer.

When carbon black is contained in the light-sensitive element, its light-shielding property lowers the photosensitivity, which can be used for adjusting the sensitivity in combination with the image-receiving element or the processing composition.

The addition amount of carbon black is preferably ^{0.001~0.2g / m 2, 0.005~0.03g / m} 2 is particularly preferred.

In the image forming method and film unit of the present invention, the developer may be present in the light-sensitive element or the processing composition element. Preferably a developer is included in the processing composition. The developer is, for example, hydroquinone, tert-butylhydroquinone,
A benzene- or naphthalene-based organic compound having a hydroxy group at the para or ortho position is used.

Further, reductic acid as described in US Pat. No. 3,615,440 and α, β-ene diol as described in US Pat. No. 3,730,716 are preferably used. Further, hydroxylamine developers as described in US Pat. Nos. 3,287,125 and 3,293,034 are particularly preferably used.

The amount of the developer used is preferably 0.1 to 40 g, and most preferably 1 to 20 g per 100 g of the processing composition.

As the developer, a 1-aryl-3-pyrazolidinone compound or an alkyl-substituted p-aminophenol described in JP-B-49-13580 may be used in combination with the developer.

The silver halide solvent may be present in the processing element, the light sensitive element and / or the image receiving element. Among them, the processing element is the most preferable. U.S. Patents 2,857,274, 2,857,275 and 2,
Suitable cyclic compounds described in No. 857,276,
Of these, uracil, urazole, 6-methyluracil and the like are preferable examples.

Further, alkali metal thiosulfates, particularly sodium or potassium salts are preferable, and U.S. Pat. No. 3,958,992,
3,976,647, 4,009,167, 4,032,538, 4,04
6,568, 4,047,954, 4,047,955, 4,107,176
And JP-A-47-330 disulfonyl methane compound and U.S. Pat.Nos. 4,126,459, 4,150,228, 4,211,559 and 4,211,562, and dihydroxypyrimidine compounds having a thioether group, U.S. Pat.
It can be selected from 4,267,254 and 4,267,256 aminothioethers. These may be used alone or in combination.When two or more cyclic imide compounds or dihydroxypyrimidine compounds having a thioether group are used in combination, white crystals may be deposited on the surface even if the prints are stored for a long period of time. There is an advantage that there is no.

The addition amount of the silver halide solvent is 10
It is preferable to contain 0.1 to 30 g per 0 g, and most preferably 0.5 to 10 g.

When this is applied by distributing the processing liquid used in this invention as a thin layer between the overlaid photosensitive element and image receiving element, the processing liquid contains a polymeric film former, thickener or thickener. Is preferred. Hydroxyethyl cellulose and sodium carboxymethyl cellulose are particularly useful for this purpose,
It is contained in the processing liquid at a concentration effective to give an appropriate viscosity according to the known principle of diffusion transfer photography. The processing liquid may further contain other auxiliaries known in the silver salt diffusion transfer method, for example, antifoggants, toning agents, stabilizers and the like. In particular, the inclusion of an oxyethylamino compound, such as triethanolamine,
It is useful for increasing the shelf life of processing solutions as described in US Pat. No. 3,619,185.

The processing liquid as described above is preferably contained in a destructible container to form a processing element. Regarding the destructible container and its material, any known material can be used, for example, U.S. Pat.
Issue, Issue 3,056,492, Issue 3,173,580, Issue 3,750,907,
It is described in detail in No. 3,833,381, No. 4,303,750, No. 4,303,751 and the like.

The image receiving element in the present invention is coated on a support carrying an image receiving layer containing a silver precipitating agent, such as baryta paper, cellulose triacetate or polyesters. Such image-receiving elements are preferably prepared by coating an optionally subbed support with a coating solution of a suitable cellulose ester in which a silver precipitating agent is dispersed, for example cellulose diacetate. The obtained layer of cellulose ester is alkali-hydrolyzed to convert at least part of the depth of the cellulose ester into cellulose. In a particularly useful embodiment, the silver precipitation layer and / or the underlying non-hydrolyzed underlayer cellulose ester, eg, the non-hydrolyzed portion of the cellulose ester layer containing cellulose diacetate, is the silver transfer layer. It contains one or more mercapto compounds suitable for improving the image tone, stability or other photographic properties. Such a mercapto compound is utilized in the invasion by diffusing from the position where it is first placed. This type of image receiving element is described in U.S. Pat. No. 3,607,269.

Further, as the mercapto compound, Japanese Examined Patent Publication No. 56-44418,
JP-A-49-120634, British patent 1276961, JP-B-56-2114
0, JP-A-59-231537 and JP-A-60-122939 are preferable.

Further, an image receiving element having an acidic polymer layer for neutralization (neutralization layer) provided between the unsaponifiable layer (timing layer) and the support is preferable.

The alkali neutralization layer used in the present invention is, for example, Japanese Patent Publication No.
The polymer acid described in -33697 or the like is used. Preferred polymer acids include maleic anhydride copolymers such as styrene-maleic anhydride copolymer, methyl vinyl ether-
(Meth) acrylic acid (co) polymers such as maleic anhydride copolymers and ethylene-maleic anhydride copolymers, for example,
Acrylic acid-alkyl acrylate copolymer, acrylic acid-alkyl methacrylate copolymer, methacrylic acid-alkyl acrylate copolymer, methacrylic acid-
Examples thereof include alkyl methacrylate copolymers. In addition to these, polymers containing sulfonic acid groups such as polystyrene sulfonic acid and acetalized products of benzaldehyde sulfonic acid and polyvinyl alcohol are also useful. Also,
The neutralization layer may contain a mercapto compound used in the timing layer. For the purpose of improving the physical properties of the membrane, these polymer acids may be mixed with a hydrolyzable alkali non-permeable polymer (particularly the above-mentioned cellulose ester is preferable) or an alkali-permeable polymer.

Specific examples of silver precipitants include heavy metals such as iron, lead, zinc, nickel, cadmium, tin, chromium, copper, cobalt, especially noble metals such as metals, silver, platinum and palladium. Other useful silver precipitants are the sulfides and selenides of precious metals, especially the sulfides of mercury, copper, aluminum, zinc, cadmium, cobalt, nickel, silver, lead, antimony, bismuth, cerium, magnesium, gold, platinum and palladium. And selenides of lead, zinc, antimony and nickel.

In particular, gold, platinum and palladium are preferably sulfides thereof.

Further, the image receiving element preferably has an image stabilizing layer for improving the image storability, and a cationic polyelectrolyte is preferable as the stabilizer, and particularly, JP-A-59-1669.
40, U.S. Patent 395899, JP-A-55-142339, JP-A-54-12602
7, the same 54-155835, the same 53-30328, the same 54-92274 water dispersion latex and U.S. Pat.
61, 3756814, the polyvinylpyridinium salt, the water-soluble quaternary ammonium salt polymer described in US Pat. No. 3,709,690, and the water-insoluble quaternary ammonium salt polymer described in US Pat.

Further, as the binder of the image stabilizing layer, cellulose acetate is preferable, and cellulose acetate having an acetylation degree of 40 to 49% is particularly preferable.

This image stabilizing layer is preferably provided between the neutralizing layer and the timing layer.

A hydrophilic polymer layer can be provided between the silver precipitation layer and the timing layer.

The hydrophilic polymer layer described in the present invention is a polymer layer which is soluble in water, and specific examples thereof include polyacrylamide, gum arabic, polyvinyl alcohol and gelatin.

A peeling layer is preferably provided on the surface of the image receiving layer in order to prevent the processing liquid from adhering to the surface of the image receiving layer during peeling after the development of the processing liquid. Preferable examples of such a release layer include gum arabic, hydroxyethyl cellulose, methyl cellulose, polyvinyl alcohol, polyacrylamide, sodium alginate, and US Pat.
Mention may be made of those described in 2,024, 3,820,999 and British Patent 1,360,653.

Further, in the present invention, a light-sensitive element obtained by coating a light-sensitive silver halide emulsion on a support is preferably used.

Any of silver bromide, silver iodobromide, silver iodochlorobromide, silver chlorobromide and silver chloride may be used as the silver halide in the photosensitive silver halide emulsion used in the present invention. A preferred silver halide is silver iodobromide or silver iodochlorobromide containing 10 mol% or less of silver iodide. Particularly preferred is 2 mol% to 10 mol%
It is a silver iodobromide containing up to silver iodide.

The average grain size of the silver halide grains in the photosensitive emulsion (the grain diameter in the case of spherical or spherical grains, the ridge length in the case of cubic grains, and the average based on the projected area) is not particularly limited. Although it is not present, it is preferably 3μ or less, more preferably 1.7μ or less, and particularly preferably
0.2 to 1.4μ.

The particle size distribution may be narrow or wide.

The silver halide grains in the photosensitive emulsion may have an equiaxed crystal form such as a cube or an octahedron, or a heteromorphic crystal form such as a sphere or a plate, or a crystal thereof. It may have a complex shape. It may consist of a mixture of particles of different crystal forms.

The silver halide grains may be composed of different phases in the inside and the surface layer, or may be composed of a uniform phase. Further, the particles may be such that the latent image is mainly formed on the surface, or may be the particles that are mainly formed inside the particle.
Grains in which the latent image is mainly formed on the surface are preferred.

The thickness of the photosensitive emulsion layer is 0.5 to 8.0 µ, particularly 0.6 to 6.0 µ, and the coating amount of silver halide grains is 0.1 to 3 g / m ² , preferably 0.2 to 1.5 g / m ² .

The light-sensitive emulsion is prepared by a method usually used as a silver halide photographic emulsion, and chemical sensitization and spectral sensitization are carried out as necessary, and the emulsion is provided with an antifoggant, a stabilizer, a hardener, a coating aid, An antistatic agent or the like may be included. A vehicle such as gelatin is used for the emulsion.

The exposure for obtaining a photographic image may be performed using a usual method. That is, any of a variety of known light sources such as natural light (daylight), a tungsten lamp, a fluorescent lamp, a mercury lamp, a xenon arc lamp, a carbon arc lamp, a xenon flash lamp, and a cathode ray tube flying spot can be used. The exposure time is 1/1000 second, which is usually used in cameras, and 1
It is possible to use an exposure time of less than 1/1000 second, for example, an exposure time of 1/10 ⁴ to 1/10 ⁶ seconds using a xenon flash lamp or a cathode ray tube, or an exposure longer than 1 second. You can also If necessary, the spectral composition of the light used for exposure can be adjusted with a color filter. Laser light can also be used for the exposure. Also electron beam, X
You may expose by the light emitted from the fluorescent substance excited by the ray, (gamma) ray, (alpha) ray, etc.

The arrangement and combination of the respective elements for combining the light-sensitive element, the image-receiving element and the processing element as described above to form a film unit are described in, for example, Neblettes, HAND BOOK OF PHOTOGRAPHY.
AND REPROGRAPHY), 7th edition, pp. 282-285, and particularly preferred embodiments are described in detail in US Pat. No. 3,350,991, which can be referred to.

The present invention can also be used in a diffusion transfer method for forming an image using an automatic processor.

Further, the present invention can be applied not only to the type in which the image receiving element and the photosensitive element are peeled off after developing the processing composition, but also to the type in which the film unit is integrally molded.

(Effects of the Invention) According to the present invention, the color tone of a silver image obtained by the silver salt diffusion transfer method can be made to have a deep color tone with increased yellow.

(Examples) Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.

Example 1. Preparation of image receiving sheet An image receiving sheet (1) was prepared by providing the following layers in order on a support polyethylene laminated paper. Numerical values in parentheses indicate the coating amount in g / m ² .

1) Neutralization layer: Cellulose acetate (acetylation degree 53%) (6), methyl vinyl ether-maleic anhydride copolymer (4), uvitex OB (trade name of Ciba-Geigy) (0.04),
1- (4-hexylcarbamoylphenyl) -2,3-dihydroimidazole-2-thione (0.25) 2) Image stabilizing layer Cellulose acetate (acetylation degree 46%) (4) The following compound (2) 3) Timing layer Cellulose acetate (degree of acetylation 55%) 4) image receiving layer Cellulose acetate (degree of acetylation 53%) (2.0), palladium sulfide (7.5 × 10 ^-4), 2-mercaptobenzimidazole (4 × 10 ^{- 3} ), 1- (4-hexylcarbamoylphenyl) -2,3-dihydroimidazol-2-thione (1.0
× 10 ^-2 ) 5) Saponification Saponification was carried out from the surface with a solution prepared by mixing 10.7 g of NaOH, 24 g of glycerin and 280 ml of methanol.

6) Release layer Butyl methacrylate-acrylic acid copolymer (molar ratio 15:85) (0.04) 2. Preparation of photosensitive sheet The following layers were provided in order on a support (black polyester film); 1) Average Silver iodobromide with a grain size of 1.3 μm (iodine content: 6.1 mol%)
And silver iodobromide with an average grain size of 0.6μ (6.1%) (0.05g / silver)
m ² ) (0.5g / m ^{2 in} silver amount), gelatin (4.7) 2) Protective layer Gelatin (0.7), polymethylmethacrylate particles (.
01), carbon black (0.01) 3. Preparation of treatment liquid Titanium dioxide 5g Potassium hydroxide 280g Uracil 90g Tetrahydropyrimidinethione 0.2g 1-phenyl-2-mercaptoimidazole 0.2g 2,4-dimercaptopyrimidine 0.2g Zinc oxide 10g Triethanolamine 60g Hydroxyethylcellulose 45g N-N-bis-methoxyethylhydroxylamine (17% aqueous solution) 260g Water 1250ml 4. Development processing The photosensitive sheet is exposed through a step wedge,
The image receiving sheet and the coated surface were superposed so that they were in contact with each other, and the treatment liquid was developed at 25 ° C. between them and peeled after 30 seconds. The results are shown in Table 1.

Example 1 An unsurfaced carbon black (0.
01) Example 2 Surface-treated carbon black with a hypochlorous acid in the protective layer of the light-sensitive material sheet (0.01) Comparative Example 1 Light-sensitive material sheet: a material in which the carbon black was removed from the protective layer Comparative Example 2 Treatment liquid: Toning agent Tetrahydropyrimidinethione 0.
Make it 14g.

From Table 1, it was found that by using the carbon black in the photosensitive sheet according to the present invention, it is possible to obtain a color tone superior to that using the conventional color tone agent.

Claims (1)

[Claims] 1. A light-sensitive element containing an image-exposed light-sensitive silver halide emulsion layer is developed with an alkali processing composition in the presence of a silver halide solvent to produce an unexposed silver halide layer in the emulsion layer. At least a part of which is a transferable silver complex salt, and at least a part of the complex salt is transferred to a silver precipitating agent-containing image receiving layer to form an image on the image receiving layer. Image forming method characterized in that the protective layer of the element contains carbon black