JP2006078615A - Color diffusion transfer film unit and image forming method using color diffusion transfer film unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color diffusion transfer film unit which ensures occurrence of less spot-like fog and a short image completion time. <P>SOLUTION: The color diffusion transfer film unit comprises: a photosensitive sheet having an image receiving layer, a white reflective layer, a light shielding layer and a silver halide emulsion layer on a first transparent support; a transparent cover sheet having a neutralization layer and a neutralization timing layer on a second transparent support; and an alkali processing composition-containing body which is spread between the photosensitive sheet and the transparent cover sheet, wherein the alkali processing composition-containing body has an optical density of ≥47 and a sodium ion content of ≤0.4 g/m<SP>2</SP>. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a color diffusion transfer film unit, and more specifically, a color diffusion transfer film unit comprising an alkaline treatment composition-containing body having both excellent light shielding properties and dye transfer properties, and such a color diffusion transfer film unit. The present invention relates to an image forming method.

  The color diffusion transfer film unit includes an integral type and a divided type. A typical example of the split type is a so-called peel apartment type. A peel-apart type color diffusion transfer film unit has a photosensitive sheet and a dye image-receiving element which are coated on separate supports, and after the image exposure, the photosensitive sheet and the dye-receiving element are superposed and an alkali is interposed therebetween. After the treatment composition-containing body is developed, the dye image transferred to the dye image-receiving layer is exposed by peeling off the dye-receiving element.

  A dye image obtained by a divided type color diffusion transfer film unit such as a peel-apart type is formed on an exposed dye image-receiving layer and directly viewed. Therefore, there is no deterioration in image quality and excellent color reproducibility is exhibited. Thus, it can be said that the excellent color reproducibility by direct visual recognition is a great advantage as compared with an integrated color diffusion transfer film unit described later that visually recognizes an image through a support. However, the division type color diffusion transfer film unit has an inconvenience in operation in which the photosensitive sheet and the image receiving element are superposed in the camera, and an alkaline processing liquid remaining after the dye image receiving element is peeled off. There is inconvenience in handling that it is easy to adhere and stick.

  On the other hand, the integrated color diffusion transfer film unit does not have such inconvenience in operation and handling and is often used by general users. An integrated color diffusion transfer film unit is a destructible container in which a dye image-receiving element, a photosensitive sheet and a neutralization timing element, and an alkaline processing composition-containing body are placed between a transparent support and another support. And have. The alkaline processing composition-containing body exits the breakable container and is developed between the image receiving element and the photosensitive sheet. The photosensitive sheet of the integrated color diffusion transfer film unit has a form coated on the same transparent support as the image receiving element and a form coated on another support. In the former form, a white reflective layer is coated between the image-receiving element and the photosensitive sheet, and in the latter form, the alkali treatment composition contains a white pigment. Therefore, in any form, the dye image transferred to the image-receiving layer is Observable with reflected light. There are many integrated color diffusion transfer film units such as Research Disclosure Vol. 151, No. 15162 (1976) and Photographic Science and Engineering Vol. 20, No. 4, July 18 (1976). In the literature.

  The integrated color diffusion transfer film unit is often incorporated in devices such as cameras and printers. The size of these devices is an important factor in deciding to purchase, and since there is a great need for “miniaturization”, the color diffusion transfer film unit to be incorporated is also expected to be miniaturized. Since the thickness of the film unit is determined by the thickness of the breakable container, it is effective to reduce the thickness of the breakable container in order to realize “miniaturization”. Specifically, it is desired that the thickness of the breakable container is about 0.1 to 1.0 mm.

  However, when the destructible container is thinned, the developed thickness of the alkali-treated composition-containing body becomes small, so that a problem that a spot-like fog occurs when light hits from the cover sheet side easily occurs. The reason for this is considered to be that when the developed thickness is reduced, the light-shielding agent blended in the alkali treatment composition for preventing fogging cannot function sufficiently. This problem is very serious because a color diffusion transfer film unit incorporated in a camera or the like may be used under direct sunlight.

  US Pat. No. 4,615,966 (Patent Document 1) describes that “the amount of the light-shielding agent may be adjusted according to the sensitivity of the photosensitive material, the amount of light to be exposed, and the time of irradiation, but an optical density of about 6 is preferable”. ing. However, as a result of research by the present inventor, when the thickness of the breakable container is 0.1 to 1.0 mm, the developed thickness of the alkali-treated composition-containing body is as thin as 1 to 80 μm. Then, it was found that the light shielding ability was insufficient, and spot fogging occurred even when the optical density was 7 times 42.

  On the other hand, when the optical density is increased to prevent fogging, there is a problem that the dye transfer progresses slowly and the image completion time becomes long. When the thickness of the alkaline processing composition-containing body is 50 μm or less, the image completion is particularly delayed. As a method for increasing the transfer speed of the dye, yellow couplers described in JP-A-2003-280150 (Patent Document 2) and JP-A-2003-84408 (Patent Document 3), and JP-A-8-286343 (Patent Document 4). And a method of blending a benzenesulfonamide compound described in Japanese Patent No. 3222978 (Patent Document 5) into a photosensitive sheet and an alkaline processing composition. However, in any of the methods, when the alkali-treated composition-containing body having a thickness of 50 μm or less is made to have an optical density that does not cause fogging, the image completion time cannot be shortened sufficiently.

U.S. Pat.No. 4,615,966 JP2003-280150 JP2003-84408 JP-A-8-286343 Patent 3222978

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a color diffusion transfer film unit that generates less spot-like fog and has a short image completion time.

As a result of intensive studies in view of the above object, the present inventor has determined that the optical density of the alkali-treated composition-containing body is 47 or more and the sodium ion content is 0.4 g / m ² or less, whereby the alkali-treated composition-containing body. The present inventors have found that a color diffusion transfer film unit having a short image completion time and having a short image completion time can be obtained even if the development thickness of the film is small.

The above problems have been achieved by the following means.
(1) A photosensitive sheet having an image receiving layer, a white reflective layer, a light-shielding layer and a silver halide emulsion layer on the first transparent support, and a neutralization layer and a neutralization timing layer on the second transparent support In a color diffusion transfer film unit comprising a transparent cover sheet and an alkali treatment composition-containing body developed between the photosensitive sheet and the transparent cover sheet, the optical density of the alkali treatment composition-containing body is 47 or more. A color diffusion transfer film unit having a sodium ion content of 0.4 g / m ² or less.
(2) The color diffusion transfer film unit according to (1), wherein the silver halide emulsion is an internal latent image type direct positive silver halide emulsion.
(3) The color diffusion transfer film unit according to (1), wherein the silver halide emulsion is a negative type silver halide emulsion.
(4) Image formation in which the color diffusion transfer film unit according to any one of (1) to (3) and an exposure head that emits light in a plurality of wavelength regions are modulated to be exposed to light according to image information. Method.

The alkaline processing composition-containing body of the color diffusion transfer film unit of the present invention has an optical density of 47 or more and a sodium ion content of 0.4 g / m ² or less. The color diffusion transfer film unit having such an alkali treatment composition-containing body is (a) less likely to generate spot-like fog when exposed to light from the cover sheet side, and (b) allows the dye to proceed quickly. Therefore, the image can be completed in a short time.

  The color diffusion transfer film unit of the present invention comprises a photosensitive sheet and a transparent cover sheet, and an alkaline processing composition-containing body developed therebetween. Since the characteristics of the present invention are mainly the characteristics of the alkaline treatment composition-containing body, the alkaline treatment composition-containing body will be described first, and then the photosensitive sheet and the transparent cover sheet will be described.

[1] Alkali processing composition-containing body The alkali-processing composition-containing body is uniformly developed on the photosensitive sheet after exposure and has a function of developing the photosensitive layer and a back surface of the transparent support of the photosensitive sheet or in the photosensitive sheet. And a function of completely shielding the photosensitive layer from outside light together with the light shielding layer provided on the surface. Therefore, the alkali-treated composition-containing body contains an alkali, a thickener, a light-shielding agent, a developer, a development accelerator for controlling development, a development inhibitor, an antioxidant for preventing the developer from deteriorating, and the like. To do.

(a) Alkali The alkali may be any one having a pH of 12 or more. Examples of alkalis include alkali metal hydroxides (eg, sodium hydroxide, potassium hydroxide and lithium hydroxide), alkali metal phosphates (eg, potassium phosphate), guanidines, quaternary amine hydroxides ( For example, tetramethylammonium hydroxide). Of these, potassium hydroxide and sodium hydroxide are preferred.

(b) Developer The developer may be any developer as long as it cross-oxidizes the dye image forming compound and does not substantially produce stain even when oxidized. Developers may be used alone or in combination of two or more, or may be used in the form of a precursor. Examples of the developer include aminophenols and pyrazolidinones. Of these, pyrazolidinones are particularly preferred because they produce less stain. Specific examples of pyrazolidinones include 1-phenyl-3-pyrazolidinone, 1-p-tolyl-4,4-dihydroxymethyl-3-pyrazolidinone, 1- (3'-methyl-phenyl) -4-methyl-4-hydroxymethyl -3-pyrazolidinone, 1-phenyl-4-methyl-4-hydroxymethyl-3-pyrazolidinone, 1-p-tolyl-4-methyl-4-hydroxymethyl-3-pyrazolidinone and the like. The developer may be blended in the alkaline processing composition-containing body or may be added to an appropriate layer of the photosensitive sheet.

(c) Light shielding agent Any material having a light shielding function can be used as a light shielding agent without any particular limitation. Examples of the light shielding agent include carbon black and degradable dyes described in US Pat. No. 4,615,966. Of these light shielding agents, carbon black is preferred. Carbon black is not limited to that obtained by a specific production method, and may be obtained by any production method. Examples of carbon black production methods include the channel method as described in Donnel Voet “Carbon Black” Marcel Dekker, Inc. (1976), the thermal method and the furnace method.

  When carbon black is used as the light-shielding agent, it is preferable that the carbon black is previously made into an aqueous dispersion. Aqueous dispersions of carbon black are very often used as paints, inks, cosmetics or photographic photosensitive materials, and as black materials or light-shielding materials. In order to prepare an aqueous dispersion of carbon black, carbon black is added to water in which an appropriate dispersant is dissolved, and a coarse disperser (for example, a high-speed stirring disperser such as a dissolver described in Japanese Patent Application No. 54-36045). ) Is used to coarsely disperse the carbon black with an average particle size of about 10 to 100 μm, and then the particle size is generally further reduced by a fine disperser (eg, sand grinder, homogenizer, colloid mill, etc.). . By this step, an aqueous dispersion of carbon black having an average particle diameter of about 0.1 to 10 μm can be obtained. Further, as described in JP-A-58-52362, after dispersing carbon black in an aqueous solution containing an organic solvent, the organic solvent may be removed to obtain an aqueous dispersion of carbon black.

  Preferable dispersants include those described in “Dispersion Technology Comprehensive Materials” (Management Development Center Publishing Department), pages 255 to 257 and pages 501 to 539. An example of a commercially available dispersant is Demol N (trade name, manufactured by Kao Corporation).

  The type and / or amount of the dispersant affects the sodium ion content described later. The type and / or amount of the dispersant must be determined so as to satisfy the condition of (b) sodium ion content in addition to the condition that (a) sufficient dispersibility is imparted to the light-shielding agent. In order to satisfy both conditions of dispersibility and sodium ion content, it is preferable that the amount of the dispersant is 2 to 100% by mass with respect to the light shielding agent.

(d) Optical density The optical density of the alkali-treated composition-containing body is 47 or more, preferably 50 or more, and particularly preferably 55 or more. If the optical density is less than 47, sufficient light shielding properties cannot be obtained, and spot fogging is easily caused. It is preferable to determine the blending amount of the light-shielding agent so that the optical density is 47 or more. Although depending on the type of the light-shielding agent to be used, it is preferable that the amount of the light-shielding agent is approximately 10 to 40% by mass in order to increase the optical density to 47 or more.

(e) Sodium ion content The sodium ion content of the alkali-treated composition-containing body is 0.4 g / m ² or less in the developed state. The sodium ion content is preferably 0.35 g / m ² or less, particularly preferably 0.25 g / m ² or less.

The content of sodium ions is determined mainly by the thickener in addition to the above-described dispersant for the sunscreen agent.
Particularly preferred as a thickener is sodium carboxymethylcellulose. Sodium carboxymethylcellulose has sufficient developability and stability. When an alkali metal salt other than sodium of polyvinyl alcohol, hydroxyethyl cellulose, or carboxymethyl cellulose is used as a thickener, the sodium ion content can be reduced. However, they do not have sufficient developability and stability and are not suitable for use alone. For this reason, it is preferable to use sodium carboxymethyl cellulose as a thickener, and also use an alkali metal salt other than sodium of polyvinyl alcohol, hydroxyethyl cellulose, and carboxymethyl cellulose.

It is preferable to adjust the degree of etherification and addition amount of sodium carboxymethylcellulose so that the sodium ion content is 0.4 g / m ² or less in the developed state. The degree of etherification of sodium carboxymethylcellulose is preferably 0.5 to 2.7, more preferably 1.0 to 2.4. The amount of sodium carboxymethyl cellulose is preferably 1 to 15% by mass, more preferably 2 to 10% by mass.

  The alkali-treated composition-containing body that satisfies the optical density and sodium ion content described above exhibits excellent light-shielding properties and dye transfer properties even when thinly developed on a photosensitive sheet. In the present specification, “thinly spread” means that the alkaline treatment composition-containing body is spread on the photosensitive sheet with a thickness of 10 to 80 μm. A preferred development thickness is 10 to 60 μm, and a more preferred development thickness is 20 to 50 μm.

[2] photosensitive sheet
(d) First transparent support The support of the photosensitive sheet may be any one that is usually used for photographic photosensitive materials. The support of the integrated color diffusion transfer film unit needs to be transparent. The support is preferably smooth. Examples of the support material include cellulose acetate, polystyrene, polyethylene terephthalate, and polycarbonate. In order to prevent light piping, the support preferably contains trace amounts of dyes or pigments such as titanium oxide. The thickness of the support of the photosensitive sheet is 25 to 350 μm, preferably 50 to 210 μm, and particularly preferably 70 to 150 μm. An undercoat layer (undercoat layer) is preferably provided on the front surface of the support. Further, on the back side of the support, a layer for curling balance or an oxygen barrier layer can be provided as necessary. The oxygen barrier layer is described in JP-A-56-78833.

(e) Image receiving layer The image receiving layer (dye image receiving layer) of the photosensitive sheet contains a mordant and a hydrophilic colloid. The image receiving layer may be a single layer or may have a structure in which layers having different mordant powers are laminated. Single-layer and multilayer image-receiving layers are described in JP-A-61-252551.

As the mordant, a polymer mordant is preferable. The polymer mordant is a polymer containing a secondary and / or tertiary amino group, a polymer having a nitrogen-containing heterocyclic moiety, a polymer containing a quaternary cation, etc., having a molecular weight of 5,000 or more, particularly preferable. Is over 10,000. The coated amount of the mordant is generally a 0.5~10 g / m ^2, preferably from 1 to 5 g / m ^2, particularly preferably 2 to 4 g / m ^2.

  Examples of the hydrophilic colloid include gelatin, polyvinyl alcohol, polyacrylamide, and polyvinyl pyrrolidone. A preferred hydrophilic colloid is gelatin.

The image receiving layer may contain an anti-fading agent. The anti-fading agent is described in JP-A-62-30620, JP-A-62-30621 and JP-A-62-215272.
The thickness of the image receiving layer may be the same as the thickness of the image receiving layer of a general color diffusion transfer film unit.

(f) White reflective layer The white reflective layer of the photosensitive sheet forms the white background of the color image. The white reflective layer usually contains a white pigment and a hydrophilic binder.

The whiteness of the white reflective layer is determined by the type of pigment, the mixing ratio of pigment and binder, and the amount of pigment applied. When the white pigment is titanium dioxide, the content of titanium dioxide is 5 to 40 g / m ² , preferably 10 to 25 g / m ² .

  The light reflectance of the white reflective layer is preferably 70% or more, and more preferably 78 to 85% for light having a wavelength of 540 nm.

  Examples of white pigments include barium sulfate, zinc oxide, barium stearate, silver flakes, silicates, alumina, zirconium oxide, sodium zirconium sulfate, kaolin, mica and titanium dioxide. Non-film-forming polymer particles such as polystyrene can also be used as a white pigment. Of these, titanium dioxide is preferable, and rutile type titanium dioxide is particularly preferable. A white pigment may be used independently and may be used 2 or more types. When two or more kinds of white pigments are used, the reflectance of the white reflective layer is easily set to a preferable value.

  The white pigment is preferably surface-treated with alumina, silica, zinc oxide or the like, and more preferably has a surface treatment amount of 5% or more. A white reflective layer containing a surface-treated white pigment exhibits a high reflectance.

  Examples of commercially available titanium dioxide include those described in DuPont's Ti-pure R931 (trade name) and Research Disclosure Magazine (hereinafter abbreviated as RD) No. 15162.

  Examples of the hydrophilic binder include alkali-permeable polymer matrices such as gelatin and polyvinyl alcohol, and cellulose derivatives such as hydroxyethyl cellulose and carboxymethyl cellulose. When the binder is gelatin, the mass ratio of the white pigment to gelatin is from 1/1 to 20/1, preferably from 5/1 to 10/1.

  The white reflective layer preferably contains an anti-fading agent. The anti-fading agent is described in JP-B-62-30620 and JP-B-62-30621.

(g) Light-shielding layer The light-shielding layer is provided between the white reflective layer and the photosensitive layer. The light shielding layer contains a light shielding agent and a hydrophilic binder.

  The light-shielding agent may be the one described in [1] (c) Light-shielding agent of the alkaline treatment composition-containing body. The content of the light-shielding agent varies depending on the sensitivity of the light-sensitive material to be shielded from light. In general, the optical density is preferably about 5 to 10.

  Any binder may be used for the light shielding layer as long as it can disperse a light shielding agent such as carbon black. A preferred binder is gelatin.

  The thickness of the light shielding layer is not particularly limited as long as the light shielding ability is exhibited and the photosensitive sheet is not too thick.

(h) Photosensitive layer The photosensitive layer is adjacent to the light-shielding layer and contains a dye image-forming compound and a silver halide emulsion. The photosensitive layer may be a multilayer composed of a silver halide emulsion layer and a dye image-forming compound layer, or a single layer containing both a silver halide emulsion and a dye image-forming compound. Hereinafter, the case of a multilayer will be described, but the same applies to the case of a single layer.

(1) Dye Image Forming Compound The dye image forming compound includes a yellow dye forming compound, a magenta dye forming compound and a cyan dye forming compound.
Specific examples of yellow dye-forming compounds include U.S. Patent 3,597,200, U.S. Patent 3,309,199, U.S. Patent 4,013,633, U.S. Patent 4,245,028, U.S. Patent 4,156,609, U.S. Patent 4,139,383, U.S. Patent 4,195,992. U.S. Pat. No. 4,148,641, U.S. Pat. No. 4,148,643, U.S. Pat. No. 4,336,322, JP-A-51-114930, JP-A-56-71072, Research Disclosure 17630 (1978), and Research Disclosure 16475 ( 1977).

  Specific examples of the magenta dye forming compound include U.S. Pat.No. 3,453,107, U.S. Pat.No. 3,544,545, U.S. Pat. U.S. Pat.No. 4,255,509, U.S. Pat.No. 4,250,246, U.S. Pat.No. 4,142,891, U.S. Pat. JP 55-36804, JP 56-73057, JP 56-71060, JP 55-134, JP 7-20901, JP 8-286343 JP-A-8-286344 and JP-A-8-292537.

  Specific examples of the cyan dye-forming compound include U.S. Patent 3,482,972, U.S. Patent 3,929,760, U.S. Patent 4,013,635, U.S. Patent 4,268,625, U.S. Pat. U.S. Pat.No. 4,195,994, U.S. Pat.No. 4,147,544, U.S. Pat.No. 4,148,642, British Patent 1,551,138, JP 54-99431, JP 52-8827, and JP 53-47823. Publication, JP-A-53-143323, JP-A-54-99431, JP-A-56-71061, European Patent (EP) 53,037, European Patent (EP) 53,040, Research Disclosure 17,630 (1978) and Research Disclosure 16,475 (1977).

  A dye image forming compound that forms a dye by coupling can also be used as the dye image forming compound. Examples of dye image-forming compounds that form dyes by coupling are disclosed in JP-A-8-286340, JP-A-9-152705, JP-A-8-357190, JP-A-8-357191, JP-A-8-357191. It is described in Japanese Patent Application Laid-Open No.9-117529.

  Positive type dye image-forming compounds can also be used. Examples of positive-type dye image-forming compounds are JP-A-4-15542, JP-A-4-155332, JP-A-4-172344, JP-A-4-17450, JP-A-4-318844, JP-A-4-356046, JP-A-5-45824, JP-A-5-45825, JP-A-5-53279, JP-A-5-107710, JP-A-5-241302, JP-A-5-241302 No. 5-107708, JP-A-5-232659 and US Pat. No. 5,192,649. The positive type dye image forming compound is preferably combined with a negative type silver halide emulsion described later.

  The positive type dye image forming compound can be dispersed by the method described in JP-A-62-215272, pages 144-146. The dispersion may contain the compounds described in JP-A No. 62-215272, pages 137 to 144. Specific examples of these dye image forming compounds include the following compounds. Dye in the following compounds represents a dye group, a dye group temporarily shortened, or a dye precursor group.

(2) Silver halide emulsion The silver halide emulsion may be any of silver chloride, silver bromide, silver iodobromide, silver chlorobromide, silver chloroiodide and silver chloroiodobromide. It may be a negative emulsion that mainly forms a latent image on the surface of silver halide grains, or an internal latent image type direct positive emulsion that mainly forms a latent image inside silver halide grains.

  The negative emulsion may be a so-called core-shell emulsion having different phases in the grain interior and grain surface layer, or may have a structure joined by epitaxial junction. The silver halide emulsion may be monodispersed or polydispersed. A method of adjusting gradation by mixing monodisperse emulsions described in JP-A-1-167743 and JP-A-4-223463 is also used.

  Internal latent image type direct positive emulsions include so-called “conversion type” emulsions and “core / shell type” emulsions. Conversion type emulsions are prepared using the difference in solubility of silver halide. The core / shell emulsion is composed of silver halide inner core (core) grains that have been subjected to metal ion doping and / or chemical sensitization, and an outer shell (shell) of silver halide that covers the photosensitive site. Regarding conversion type emulsion and / or core / shell type emulsion, U.S. Patent 2,592,250, U.S. Patent 3,206,313, British Patent 1,027,146, U.S. Patent 3,761,276, U.S. Pat. Patent No. 2,563,785, US Pat. No. 3,551,662, US Pat. No. 4,395,478, West German Patent No. 2,728,108, US Pat. No. 4,431,730 and the like.

  When an internal latent image type direct positive emulsion is used, it is necessary to give surface fog nuclei by light or a nucleating agent after image exposure. Examples of the nucleating agent include hydrazines described in U.S. Pat.No. 2,563,785 and U.S. Pat.No. 2,588,982, hydrazines and hydrazones described in U.S. Pat. , Quaternary salt compounds described in U.S. Pat.No. 3,719,494, U.S. Pat. A thiourea-linked acylhydrazine described in U.S. Pat.No. 4,030,925, U.S. Pat.No. 4,031,127, U.S. Pat.No. 4,245,037, U.S. Pat. And thioamide rings, triazoles, tetrazoles and other heterocyclic groups described in U.S. Patent 4,080,270, U.S. Patent 4,278,748, British Patent 2,011,391B, etc. Acyl hydrazine compounds are preferred.

  The crystal habit of silver halide grains has regular crystals such as cubes, octahedrons, tetradecahedrons, spherical crystals, irregular crystal systems such as high aspect ratio flat plates, twins Any of those having a crystal defect such as a plane, a composite system thereof, or the like may be used.

  Other examples of silver halide emulsions include U.S. Pat. No. 4,500,626, column 50, U.S. Pat. No. 4,628,021, RD No. 17,029 (1978), RD No. 17,643 (December 1978) 22-23, RD No. 18,716. (November 1979) 648, RD No. 307,105 (November 1989) 863-865, JP 62-253159, JP 64-13546, JP 2-236546, JP 3-236 110555 and Graffkide, "Physics and Chemistry of Photography", published by Paul Monte (P. Glafkides, Chemie et Pisique Photographique, Paul Montel, 1967), "Photoemulsion Chemistry" by Duffin, Focal Press (GFDuffin, Photographic) Emulsion Chemistry, Focal Press, 1966), “Production and Coating of Photoemulsions” by Zerikman et al., Published by Focal Press (VLZelikman et al., Making and Coating Photographic Emulsion, Focal Press, 1964), etc. What was prepared using is mentioned.

  The photosensitive silver halide emulsion is generally a chemically sensitized silver halide emulsion. For the chemical sensitization of the photosensitive silver halide emulsion, a known chalcogen sensitizing method such as a sulfur sensitizing method, a selenium sensitizing method, a tellurium sensitizing method, gold, platinum, palladium, etc. The noble metal sensitizing method and reduction sensitizing method used can be used alone or in combination (for example, JP-A-3-110555, JP-A-5-241267, etc.). Such chemical sensitization can also be carried out in the presence of a nitrogen-containing heterocyclic compound (Japanese Patent Laid-Open No. 62-253159). An antifoggant can be added after the chemical sensitization. Specifically, methods described in JP-A Nos. 5-45833 and 62-40446 can be used. When the nitrogen-containing heterocyclic compound having a mercapto group described in JP-A-62-40446 is used, it is preferably added after chemical sensitization of the photosensitive silver halide emulsion.

The pH during chemical sensitization is preferably 5.3 to 10.5, more preferably 5.5 to 8.5, and the pAg is preferably 6.0 to 10.5, more preferably 6.8 to 9.0. The coating amount of the photosensitive silver halide is preferably in the range of 1 mg / m ² to 10 g / m ² in terms of silver, and more preferably 10 mg / m ² to 10 g / m ² .

  In the process of preparing the photosensitive silver halide emulsion, it is preferable to carry out so-called desalting to remove excess salt. Desalting may be performed by using a Nudell water washing method in which gelatin is gelled, and inorganic salts composed of polyvalent anions (for example, sodium sulfate), anionic surfactants, anionic polymers (for example, sodium polystyrene sulfonate) Alternatively, a precipitation method using a gelatin derivative (eg, aliphatic acylated gelatin, aromatic acylated gelatin, aromatic carbamoylated gelatin, etc.) may be used. Of these, the precipitation method is preferably used.

The photosensitive silver halide emulsion may contain heavy metals such as iridium, rhodium, platinum, cadmium, zinc, thallium, lead, iron and osmium. One kind of these compounds may be contained, or two or more kinds may be contained. The content depends on the purpose of use, but is generally about 10 ^-9 to 10 ^-3 mol per mol of silver halide. The heavy metal may be uniformly dispersed in the particles, or may be localized inside or on the surface of the particles. Specifically, heavy metal-containing emulsions described in JP-A-2-365542, JP-A-1-16637, JP-A-5-181246 and the like are preferable.

  In the grain formation stage of the photosensitive silver halide emulsion, rhodan salts, ammonia, tetrasubstituted thioether compounds, organic thioether derivatives described in JP-B-47-11386, or organic thioether derivatives described in JP-A-53-144319 are used as silver halide solvents. A sulfur compound or the like can be used.

  For other conditions, see Graffkide's "Photo Physics and Chemistry" published by Paul Monte (P. Glafkides, Chemie et Pisique Photographique, Paul Montel, 1967), Duffin's "Photo Emulsion Chemistry", Focal Press ( GFDuffin, Photographic Emulsion Chemistry, Focal Press, 1966), “Manufacture and coating of photographic emulsions” by Zerikman et al., Published by Focal Press, Inc. (VLZelikman et al. Please refer to. That is, any of an acidic method, a neutral method, and an ammonia method may be used, and any one of a one-side mixing method, a simultaneous mixing method, and a combination thereof may be used as a form for reacting a soluble silver salt and a soluble halogen salt. In order to obtain a monodisperse emulsion, the simultaneous mixing method is preferred. A reverse mixing method in which particles are formed in the presence of excess silver ions can also be used. As one type of the simultaneous mixing method, a so-called controlled double jet method in which pAg in a liquid phase produced by silver halide is kept constant can be used.

  In order to promote grain growth, the addition concentration, addition amount, and addition rate of silver salt and halogen salt to be added may be increased (Japanese Patent Laid-Open Nos. 55-142329, 55-158124, US Pat. No. 3,650,757). Issue). The reaction solution may be stirred by a general method. The temperature and pH of the reaction solution during the formation of silver halide grains may be set according to the purpose, but a preferable pH range is 2.3 to 8.5, and a more preferable pH range is 2.5 to 7.5.

  Spectral sensitizing dyes can be used in combination with negative emulsions and internal latent image type direct positive emulsions. Specific examples thereof include JP-A-59-180550, JP-A-60-140335, RD17029, US Patent 1,846,300, US Patent 2,078,233, US Patent 2,089,129, US Patent 2,165,338, US Patent 2,231,658, US Patent. No. 2,917,516, U.S. Patent 3,352,857, U.S. Patent 3,411,916, U.S. Patent 2,295,276, U.S. Pat. No. 3,335,010, US Pat. No. 3,352,680, US Pat. No. 3,384,486, US Pat. No. 3,623,881, US Pat. No. 3,718,470, US Pat. No. 4,025,349 and the like.

(3) Composition of photosensitive layer For reproduction of natural colors by the subtractive color method, an emulsion spectrally sensitized with a spectral sensitizing dye in a certain wavelength range and a dye having selective spectral absorption in the same wavelength range are provided. A photosensitive layer containing at least one combination with a dye image forming compound is used.

  The emulsion and the dye image-forming compound may be separate layers, or the emulsion and the dye image-forming compound may be contained in one layer. When the dye image-forming compound is coated and has absorption in the spectral sensitivity range of the emulsion combined therewith, a separate layer is preferred.

The emulsion layer may be composed of emulsions having different sensitivities. An arbitrary layer may be provided between the emulsion layer and the dye image-forming compound layer. For example, when a layer containing a nucleation development accelerator described in JP-A-60-173541 or a partition layer described in JP-B-60-15267 is provided, the color image density can be increased, and reflection When the layer is provided, the sensitivity of the photosensitive sheet can be increased. The reflective layer is a layer containing a white pigment and a hydrophilic binder, a preferred white pigment is titanium oxide, and a preferred hydrophilic binder is gelatin. The coating amount of titanium oxide is preferably from ^{0.1 g / m 2 ~8g / m} 2, and more preferably ^{0.2 g / m 2 ~4g / m} 2. Examples of the reflective layer are described in JP-A-60-91354.

  In the case of a photosensitive layer having a multilayer structure, it is preferable that a blue-sensitive emulsion combination unit, a green-sensitive emulsion combination unit, and a red-sensitive emulsion combination unit are sequentially arranged from the exposure side. Arbitrary layers can be provided between the respective emulsion layer units as required. In order to prevent the undesired influence of the development effect of one emulsion layer on other emulsion layer units, it is preferable to provide an intermediate layer.

  The thickness of the photosensitive layer is not particularly limited as long as sufficient color reproducibility is exhibited and the photosensitive sheet is not excessively thick.

(i) Others The photosensitive sheet has an irradiation prevention layer, a UV absorber layer, a protective layer, and the like as required.
The thickness of the photosensitive sheet is not particularly limited as long as the color diffusion transfer film unit is not too thick.

[3] Transparent cover sheet
(j) Second transparent support The support of the transparent cover sheet may be any smooth transparent support usually used for photographic light-sensitive materials. Preferred examples of the support include cellulose acetate, polystyrene, polyethylene terephthalate, and polycarbonate. The support preferably contains a trace amount of dye to prevent light piping. An undercoat layer is preferably provided on the support.

(k) Layer having neutralization function The layer having a neutralization function (neutralization layer) is a layer containing an acidic substance in an amount sufficient to neutralize the alkali introduced from the alkaline treatment composition-containing body. If necessary, a multilayer structure composed of layers such as a neutralization rate adjusting layer (neutralization timing layer) and an adhesion reinforcing layer may be used.

  A preferred acidic substance is a substance containing an acidic group having a pKa of 9 or less (or a precursor group that generates an acidic group of pKa 9 or less by hydrolysis), and a more preferred acidic substance is oleic acid described in US Pat. No. 2,983,606. Higher fatty acids such as polymers of acrylic acid, methacrylic acid or maleic acid as disclosed in US Pat. No. 3,362,819 and their partial esters or acid anhydrides; as disclosed in French Patent No. 2,290,699 A copolymer of acrylic acid and acrylic acid ester; a latex type acidic polymer as disclosed in US Pat. No. 4,139,383 and RD No. 16102 (1977). In addition, U.S. Pat.No. 4,088,493, JP-A-52-153739, JP-A-53-1023, JP-A-53-4540, JP-A-53-4541, JP-A-53-4542 Acidic substances disclosed in Japanese Patent Publication No. Gazette etc. are also preferable.

  Other examples of acidic polymers (acidic polymers) include copolymers of vinyl monomers such as ethylene, vinyl acetate, vinyl methyl ether and maleic anhydride, and their n-butyl esters, copolymers of butyl acrylate and acrylic acid. Mention may be made of polymers, cellulose and acetate hydrodiene phthalate.

  The acidic polymer can be used by mixing with a hydrophilic polymer. Examples of the hydrophilic polymer include polyacrylamide, polymethylpyrrolidone, polyvinyl alcohol (including partially saponified product), carboxymethyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, polymethyl vinyl ether and the like. Of these, polyvinyl alcohol is preferred. A polymer other than the hydrophilic polymer, such as cellulose acetate, may be mixed with the acidic polymer.

  The coating amount of the acidic polymer is determined by the amount of alkali in the alkaline treatment composition-containing body. The equivalent ratio of acidic polymer to alkali per unit area is preferably 0.9 to 2.0. If the amount of the acidic polymer is too small, the hue of the transfer dye changes or stains occur on the white background. When the amount is too large, problems such as a change in hue or a decrease in light resistance occur. A more preferred equivalent ratio is 1.0 to 1.3. If the amount of the hydrophilic polymer to be mixed is too large or too small, the quality of the photograph is deteriorated. The mass ratio of the hydrophilic polymer to the acidic polymer is 0.01 to 10, preferably 0.1 to 3.0.

  Additives can be incorporated into the neutralization layer for various purposes. For example, a general hardening agent may be added for hardening of the neutralizing layer, or a polyhydric hydroxyl compound such as polyethylene glycol, polypropylene glycol, or glycerin may be added to improve the brittleness of the film. Good. In addition, an antioxidant, a fluorescent brightening agent, a development inhibitor, a precursor thereof, and the like can be added as necessary.

  The neutralization timing layer used in combination with the neutralization layer has low alkali permeability such as gelatin, polyvinyl alcohol, partially acetalized polyvinyl alcohol, cellulose acetate, and partially hydrolyzed polyvinyl acetate. Polymers having a lactone ring, polymers having a lactone ring, and the like are useful.

  Among them, a timing layer using cellulose acetate disclosed in JP-A-54-136328, US Pat. No. 4,267,262, US Pat. No. 4,009,030, US Pat. No. 4,029,849, etc .; JP-A 54-128335 , JP 56-69629, JP 57-6843, U.S. Pat.No. 4,056,394, U.S. Pat.No. 4,061,496, U.S. Pat.No. 4,199,362, U.S. Pat.No. 4,250,243, U.S. Pat.No. 4,256,827, U.S. Pat. Latex polymer obtained by copolymerizing a small amount of a hydrophilic comonomer such as acrylic acid disclosed in Japanese Patent No. 4,268,604, etc .; a monoacrylic ester or monomethacrylic ester of a polyhydric alcohol disclosed in JP-A-11-2890 A polymer having a lactone ring disclosed in U.S. Pat. No. 4,229,516; other JP-A-56-25735, JP-A-56-97346, JP-A-57-6842, Tsu Pas Patent (EP) 31,957A1 JP, European Patent 37,724A1, JP-polymers disclosed in European Patent 48,412A1 No. etc. are particularly useful.

In addition, those described in the following documents can also be used.
U.S. Patent 3,421,893, U.S. Patent 3,455,686, U.S. Patent 3,575,701, U.S. Patent 3,778,265, U.S. Patent 3,785,815, U.S. Patent 3,847,615, U.S. Patent 4,088,493, U.S. Patent 4,123,275, U.S. Patent No. 4,148,653, U.S. Pat. No. 4,201,587, U.S. Pat. No. 4,288,523, U.S. Pat. No. 4,297,431, West German Patent Application (OLS) 1,622,936, West German Patent Application 2,162,277, RD 15162, No. 151 (1976).

  The neutralization timing layer was disclosed in US Pat. No. 4,009,029, West German Patent Application (OLS) 2,913,164, West German Patent Application 3,014,672, Japanese Patent Laid-Open No. 54-155837, Japanese Patent Laid-Open No. 55-138745, etc. It may contain a development inhibitor and / or a precursor thereof, a hydroquinone precursor disclosed in US Pat. No. 4,201,578, other photographic additives or a precursor thereof. Further, the provision of the auxiliary neutralization layer described in JP-A-63-168648 and JP-A-63-168649 is effective in reducing changes in transfer density over time after processing.

  The neutralization timing layer may contain a plurality of these materials. A plurality of materials may be included in one layer, or may be included in each of the plurality of layers.

(l) Other layers The transparent cover sheet may have a back layer, a protective layer, a filter dye layer and the like as a layer having an auxiliary function in addition to the layer having a neutralizing function.

  The back layer is provided for adjusting the curl and imparting slipperiness. The back layer may contain a filter dye. The protective layer is mainly used to prevent adhesion to the cover sheet back surface and adhesion to the photosensitive material protective layer when the photosensitive material and the cover sheet are overlapped. If the transparent cover sheet contains a dye, the sensitivity of the photosensitive layer can be adjusted. A filter dye may be added to the support of the cover sheet, the layer having a neutralizing function, the back layer, the protective layer, the capture mordant layer, or the like. A layer of filter dye alone may be provided.

[4] Others At least one of the photosensitive sheet, the transparent cover sheet, and the alkaline processing composition-containing body is a development accelerator described in JP-A No. 62-215272, pages 72 to 91, a hardening agent described in pages 146 to 155, Surfactant described on pages 201-210, fluorinated compound described on pages 210-222, thickener described on pages 225-227, antistatic agent described on pages 227-230, described on pages 230-239 The polymer latex may contain a matting agent described on page 240. Further, tertiary amine latex described in JP-A-6-273907, JP-A-7-134386, JP-A-7-175193, and JP-A-7-287372 may be contained.

  The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

Example 1
1. Preparation of Photosensitive Sheet A photosensitive sheet (photosensitive sheet 101) having the configuration shown in Tables 1 to 4 was prepared. The emulsions in the table were prepared by the method shown in Table 5.

The compounds used for the emulsion preparation are summarized below.

  The compounds used for the production of the photosensitive sheet (photosensitive sheet 101) are shown below.

2. Production of Transparent Cover Sheet Each layer shown in Table 7 was provided on a 75 μm thick polyethylene terephthalate transparent support to produce a cover sheet 101.

  The chemical structural formulas of the compounds used in the transparent cover sheet are shown below.

3. Preparation of alkaline treatment composition-containing body Next, alkaline treatment composition-containing bodies (treatment liquids 101 to 108) having the following compositions were prepared.
Carbon Black See Table 8 Additive (23) See Table 8 Thickener (Sodium Carboxymethylcellulose) See Table 8 Thickener (Additive (14)) See Table 8 Potassium Nitrite (anhydrous) 1.90 g
5-Methylbenzotriazole 2.25 g
1-phenyl-4-hydroxymethyl-4-methyl
-3-Pyrazolidone 16.0 g
Potassium hydroxide 50.2 g
Zinc nitrate 0.60 g
Benzyl alcohol 2.41 g
Water A total of 1 kg of the treatment liquid having the above composition was filled in a container capable of being broken by pressure in an amount of 0.3 g.

  Using the photosensitive sheet 101, the cover sheet 101, and processing solutions (alkali processing compositions) 101 to 108, color diffusion transfer photographic units 101 to 108 were produced by the method described in JP-A-7-159931. After this color diffusion transfer photographic unit was loaded into the camera, it was exposed from the transparent cover sheet side, and developed by developing the processing solution with a pressure roller so that the thickness between the sheets became 50 μm. The development process was performed at 25 ° C. The reflection density was measured using a color densitometer after 5 minutes from the development process and after 1 day. Further, 80,000 LUX xenon light was irradiated from the transparent cover sheet side for 1 minute immediately after the development, and the number and size of spots (black spots having a diameter of 0.2 to 3 mm) generated by light leakage were examined.

The optical density of the alkali-treated composition-containing body was measured as follows. First, weigh exactly 5.00 g from the alkali-treated composition-containing body, and add water to make a 500 mL solution. Aliquot 5 mL from this solution and add water to make a 500 mL dilution. The diluted solution was irradiated with light having a wavelength of 550 nm, and the absorbance at a wavelength of 550 nm was measured (referred to as D550) using a spectrophotometer. The measured value D550 is expressed by the following formula (1):
Optical density = D550 × developed thickness (μm) × specific gravity of the alkaline treatment composition-containing body (1)
And the optical density was determined. The control was water and a 10 mm thick cell was used.

  The results are shown in Table 8.

注1 含有量は、カラー拡散転写フイルムユニット１m²当たりの量を示す。
注2 遮光性の評価は、次のとおりとした。
◎：光漏れが生じていない
○：直径0.2〜0.3 mmのスポットが僅かに生じているが実用上問題無い。
×：直径１mmのスポットが多数生じており、実用上支障が有る。
××：全面にスポットが生じており、光漏れが著しい。

Note 1 Content indicates the amount per 1 m ^{2 of} color diffusion transfer film unit.
Note 2 The evaluation of light shielding properties was as follows.
A: No light leakage occurs. B: A spot having a diameter of 0.2 to 0.3 mm is slightly generated, but there is no practical problem.
X: A lot of spots having a diameter of 1 mm are generated, and there are practical problems.
XX: Spots are generated on the entire surface, and light leakage is significant.

As can be seen from Table 8, when an alkali treatment composition (101 to 104) having an optical density of 47 or more and a sodium ion content of 0.4 g / m ² or less is used, the magenta after 5 minutes The highest concentration was close to the concentration after 1 day. Thus, it can be said that the reason why the high concentration was exhibited after 5 minutes was that the transfer was sufficiently fast. These color diffusion transfer film units (101 to 104) were excellent in light shielding properties.

Example 2
A photosensitive sheet 201 was prepared as a photosensitive sheet, and the processing liquids 201 to 208 were used as the alkaline processing composition-containing bodies of the respective color diffusion transfer film units, and the unit in the same manner as in Example 1 except that the developing thickness of the processing liquid was changed. Was fabricated and the performance was evaluated.

  Photosensitive sheets (photosensitive sheet 201) having the layer structures shown in Tables 9 to 12 below were produced.

  The compounds used for the production of the photosensitive sheet (photosensitive sheet 201) are shown below.

  Three types of silver halide emulsions (surface latent image type) of J, K, and L were prepared by the following preparation methods. The shapes of emulsions J, K, and L are summarized in Table 14. In preparing the emulsions J, K, and L, low molecular weight gelatin having an average molecular weight of 20,000 or less was used, and deionized gelatin having a Ca content of 100 ppm or less was used.

Emulsion K:
Emulsion K was prepared as follows.
0.75 liters of gelatin aqueous solution containing 0.005 mol of potassium bromide and 1.1 g of low molecular weight gelatin, 26.5 mL of silver nitrate aqueous solution with a concentration of 0.58 mol / liter, potassium bromide concentration of 0.42 mol / liter, low molecular weight gelatin concentration of 1.5% by mass 46.4 mL of the aqueous solution was simultaneously mixed for 1 minute by the double jet method with vigorous stirring. During this period, the gelatin aqueous solution was kept at 35 ° C. After adding 0.5 g of potassium bromide, the temperature was raised to 75 ° C. with a gradient of 1.5 ° C. per minute.

  After reaching 75 ° C., 0.16 liter of gelatin solution containing 16% by mass of deionized gelatin and 5 mL of 4.9% sulfuric acid aqueous solution were added. Next, an aqueous silver nitrate solution having a concentration of 1.88 mol / liter and an aqueous potassium bromide solution having a concentration of 1.88 mol / liter are used while increasing the flow rate of the gelatin solution containing sulfuric acid (the flow rate at the end is equal to the flow rate at the start). 3.5 times) and added over 44 minutes by the double jet method. The amount of silver nitrate aqueous solution added was 366 mL, and the amount of potassium bromide aqueous solution was 375 mL.

  Next, 0.08 liter of gelatin solution containing 14% by mass of deionized gelatin having a Ca content of 100 ppm or less and 2 mg of sodium benzenethiosulfate were added. Subsequently, an aqueous silver nitrate solution with a concentration of 1.88 mol / liter and an aqueous potassium bromide solution with a concentration of 1.88 mol / liter were used while increasing the flow rate of the gelatin solution containing sodium benzenethiosulfate (the flow rate at the end was Was added over 11 minutes by the double jet method. The amount of silver nitrate aqueous solution added was 157 mL, and the amount of potassium bromide aqueous solution was 163 mL.

After adding 4.6 g of potassium bromide, it was washed with water by a conventional flocculation method. After adding deionized gelatin, 2-phenoxyethanol and methyl p-hydroxybenzoate, the pH was adjusted to 5.8 and pAg 8.8 to contain 1.35 mol of silver and 84 g of gelatin per kg of emulsion. After heating 0.74 kg of the mixture containing silver nitrate and potassium bromide thus obtained to 55 ° C., 0.5 g of potassium iodide, 4.2 × 10 ⁻⁴ mol of sensitizing dye (6), and sensitizing dye 5.4 × 10 ⁻⁴ mol of (7) was added and aged for 30 minutes. Next, potassium thiocyanate 5.0 × 10 ⁻⁴ mol, potassium tetrachloroaurate 1.4 × 10 ⁻⁵ mol, and sodium thiosulfate 1.2 × 10 ⁻⁵ mol were added and aged for 60 minutes. × 10 ^-3 mol was added to complete the emulsion preparation compound E-5 to 3.2 × 10 ^-4 mol per mol to after the maturing.

  As a result of observation by an electron microscope, the average value of the particle thickness hi (= Σhi × ni / Σni) was 0.135 μm, and the average value of the sphere equivalent diameter Di of the particles (= ΣDi × ni / Σni) was 1.15 μm. The equivalent sphere diameter indicates the diameter of a circle having an area equal to the projected area when viewed from the main plane direction of each particle. The average aspect ratio represented by the average value of the equivalent sphere diameter Di / the average value of the particle thickness hi was 8.5.

Emulsion J:
Emulsion J was prepared in the same manner as Emulsion K except that sensitizing dye (9) was added in an amount of 9.2 × 10 ⁻⁴ mol instead of sensitizing dye (6) and sensitizing dye (7).

Emulsion L:
Instead of sensitizing dye (6) and sensitizing dye (7), sensitizing dye (1) is 8.4 × 10 ⁻⁴ mol, sensitizing dye (2) is 2.6 × 10 ⁻⁵ mol and sensitizing dye (3). Emulsion L was prepared in the same manner as Emulsion K except that 1.7 × 10 ⁻⁴ mol was added. .

  The compounds used for the emulsion preparation are summarized below.

Next, an alkaline treatment composition-containing body (treatment liquids 201 to 208) having the following composition was produced.
Carbon Black See Table 15 Additive (23) See Table 15 Thickener (Sodium Carboxymethylcellulose) See Table 15 Potassium sulfite (anhydrous) 1.90 g
5-methylbenzotriazole 6.75 g
1-phenyl-4-hydroxymethyl-4-methyl
-3-Pyrazolidone 13.6 g
Potassium hydroxide 52.7 g
Zinc nitrate 0.60 g
Benzyl alcohol 2.41 g
Water A total of 1 kg of the treatment liquid having the above composition was filled in a container capable of being broken by pressure in an amount of 0.3 g.

  Using the photosensitive sheet 201, the cover sheet 101, and the processing solutions 201 to 208, color diffusion transfer photographic units 201 to 208 were produced by a method such as JP-A-7-159931. This color diffusion transfer photographic unit was developed with an exposure development processor incorporating a three-color LED exposure machine of blue, green and red. After loading the color diffusion transfer photographic unit 201-208 into the exposure development processor, the cover sheet is exposed using the LED as the light source, and the processing liquid is developed with a pressure roller to a thickness of 39 μm between both sheets. Then, development was performed. The development process was performed at 25 ° C., and the reflection density was measured after 5 minutes from the development process and after 1 day using a color densitometer. Further, the optical density and the light shielding property of the alkali-treated composition-containing body were determined in the same manner as in Example 1.

  The results are summarized in Table 15.

注1 含有量は、カラー拡散転写フイルムユニット１m²当たりの量を示す。
注2 遮光性の評価は、次のとおりとした。
◎：光漏れが生じていない
○：直径0.2〜0.3 mmのスポットが僅かに生じているが実用上問題無い。
×：直径１mm程度のスポットが多数生じており、実用上支障が有る。
××：全面にスポットが生じており、光漏れが著しい。

Note 1 Content indicates the amount per 1 m ^{2 of} color diffusion transfer film unit.
Note 2 The evaluation of light shielding properties was as follows.
A: No light leakage occurs. B: A spot having a diameter of 0.2 to 0.3 mm is slightly generated, but there is no practical problem.
X: A lot of spots having a diameter of about 1 mm are generated, which has a practical problem.
XX: Spots are generated on the entire surface, and light leakage is significant.

When using an alkali treatment composition (201 to 204) having an optical density of 47 or more and a sodium ion content of 0.4 g / m ² or less, the maximum density of magenta after 5 minutes is the density after 1 day. It was close to. This indicates that the magenta dye transfer occurred very quickly. Further, these color diffusion transfer film units (201 to 204) were excellent in light shielding properties.

Claims (4)

A photosensitive sheet having an image receiving layer, a white reflective layer, a light shielding layer and a silver halide emulsion layer on the first transparent support, and a transparent cover sheet having a neutralization layer and a neutralization timing layer on the second transparent support And a color diffusion transfer film unit comprising an alkaline processing composition-containing body developed between the photosensitive sheet and the transparent cover sheet, wherein the optical density of the alkaline processing composition-containing body is 47 or more, sodium A color diffusion transfer film unit having an ion content of 0.4 g / m ² or less.   2. A color diffusion transfer film unit according to claim 1, wherein the silver halide emulsion is an internal latent image type direct positive silver halide emulsion.   2. The color diffusion transfer film unit according to claim 1, wherein the silver halide emulsion is a negative silver halide emulsion.   4. An image forming method comprising: using the color diffusion transfer film unit according to any one of claims 1 to 3; and an exposure head that emits light in a plurality of wavelength ranges, and performing exposure by modulating the light amount according to image information. Method.