JPH053577B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to materials for diffusion transfer. In particular, it relates to a photosensitive material for silver complex diffusion transfer. The principle of silver complex diffusion transfer method (hereinafter referred to as DTR method) is described in US Pat. No. 2,352,014 and is well known. In the DTR method, an imagewise exposed silver halide emulsion layer is superimposed in contact with an image-receiving layer in the presence of a developing agent and a silver halide complexing agent. In the exposed parts of the silver halide emulsion layer, the silver halide is developed to silver (chemical development) and therefore cannot be dissolved or diffused any further. In the unexposed areas, the silver halide is converted to a soluble silver complex salt, which is transferred to the image-receiving layer,
There they form a silver image, usually in the presence of physical development nuclei. When an original is photographed by camera work using a light-sensitive material for diffusion transfer, image reproducibility is important, and many methods have been proposed to date. DTR to obtain high contrast and sharp images
A common method in photosensitive materials for use in photosensitive materials is to utilize antihalation methods and provide an antihalation layer containing a black pigment such as carbon black. However, even if such a method is used, it cannot be said to be sufficient, and particularly in the case of low silver, the image reproducibility deteriorates significantly, which has hindered the low silver. Furthermore, in the case of low silver, image reproducibility deteriorates significantly in high-temperature processing, and there has been a need for a light-sensitive material for diffusion transfer that is less dependent on processing conditions. The present inventors have studied emulsion factors based on the assumption that the emulsion factors of silver halide emulsions may also affect image reproducibility. Conventionally, in light-sensitive materials for diffusion transfer in this field, silver chloride-based emulsions with an average grain size of 0.35 μm or less have often been used. This is because it is possible to provide a light-sensitive material for diffusion transfer that has excellent transfer efficiency to the image-receiving material and has a silver amount (Ag equivalent amount) of 1.2 g/m ² or more, which is also favorable for image reproducibility. It seems so. However, in the conventional technology, it is currently impossible to deal with the deterioration of image reproducibility when aiming for low silver. The present inventors discovered that conventional emulsions with an average grain size of 0.35μ or less were rather unfavorable for image reproducibility, and as a result of various studies, they devised a method to improve image reproducibility. I found it. That is, a silver halide emulsion layer in which the average grain size of the silver halide emulsion grains is in the range of 0.38μ or more and 0.6 or less, and in which 90% by weight or more of the total grains are within ±40% of the average grain size. The method is to use a light-sensitive material for diffusion transfer that has the following characteristics. One object of the present invention is to provide a light-sensitive material for diffusion transfer that has excellent image reproducibility. Another object of the present invention is to provide a light-sensitive material for diffusion transfer that is less dependent on processing conditions. Other objects of the invention will become apparent from the following description. The silver halide grains used in the present invention have an average grain size of 0.38 μm or less, and 90% by weight or more of all grains are within ±40% of the average size. In the DTR processing process, unexposed silver halide grains come into contact with a silver halide complexing agent, are dissolved, and are diffusely transferred to the image-receiving layer, but the dissolution rate depends on the grain size and It is generally believed that the smaller the size, the faster the speed. One of the factors governing image reproducibility is thought to be the chemical development rate of exposed silver halide grains. All of the exposed silver halide grains are converted to silver through chemical development, while all of the unexposed grains are dissolved and diffused. It is thought that lateral diffusion in the layer will be reduced and fine line reproducibility will be improved. Conventional emulsions with an average grain size of 0.35μ or ^less have a high dissolution rate and transfer and development of the image-receiving layer is thought to occur quickly. Reproducibility appears to be at a good level. However, in the case of low silver
As the amount of silver decreases, the rate of dissolution appears to become relatively faster compared to the rate of chemical development, and image reproducibility decreases. Therefore, emulsions with an average grain size smaller than 0.38μ are particularly suitable for emulsions with an average grain size of 0.45g/m ² or more and 1.1g/m ²
In the range of silver amount (Ag equivalent value) equivalent to:
Image reproducibility deteriorates, which is not preferable. On the other hand, simply increasing the average particle size did not improve image reproducibility. This is presumed to be due to the balance between chemical development rate and dissolution rate, but no favorable results were obtained. In particular, the average particle size
When it exceeded 0.60μ, image reproducibility decreased. The average particle size is in the range of 0.38μ or more and 0.6μ or less,
Moreover, it was found that only particles in which 90% by weight or more of all particles were contained within ±40% of the average particle size improved image reproducibility. Particularly preferably,
This is a case where the average particle size is in the range of 0.45μ or more and 0.55μ or less, and 90% by weight or more of all particles are within ±40% of the average particle size. In the present invention, an emulsion in which 90% by weight or more of all grains are contained within ±40% of the average grain size is referred to as monodisperse, and such an emulsion is referred to as a monodisperse emulsion. Since non-monodisperse emulsions have a grain size distribution, the dissolution rate of individual grains is thought to have a distribution, and therefore the relative balance between chemical development rate and dissolution rate is thought to vary. It is assumed that the development speed also causes a distribution, and it is inferred that the amount of silver halide effective for image reproduction decreases, resulting in a decrease in image reproducibility. When the silver halide emulsion layer of the present invention is combined with an antihalation layer containing a black pigment, image reproducibility can be further improved. Furthermore, when the silver halide emulsion layer of the present invention is combined with an antihalation layer containing a white pigment, image reproducibility can be further improved.
Furthermore, image reproducibility can also be improved when combined with an antihalation layer containing a combination of the above-mentioned black pigment and white pigment. Further, the present invention is effective in the case of an emulsion layer having a silver content (Ag equivalent value) corresponding to 0.45 g/m ² or more and 1.1 g/m ² or less. At silver amounts exceeding 1.1 g/m ² , image reproducibility does not depend greatly on the monodispersity of the emulsion, but at silver amounts below 1.1 g/m ² , it becomes susceptible to the monodispersity of the emulsion. . When the amount of silver is less than 0.45 g/m ² , image reproducibility is greatly reduced. The influence of the amount of silver is particularly noticeable in the deterioration of image reproducibility during high-temperature processing, and this seems to be related to the dissolution rate during the dissolution process of silver halide in DTR. That is, silver halide grains that are not monodisperse are thought to have uneven dissolution rates and are thought to cause a lot of loss during DTR development. especially,
In high-temperature processing at 28°C or higher, it is estimated that image reproducibility is likely to deteriorate because the influence of dissolution rate increases. Hydrophilic binders that are advantageously used for preparing light-sensitive emulsions include lime-treated gelatin, acid-treated gelatin, gelatin derivatives (e.g. Japanese Patent Publication No. 38-4854)
No., No. 39-5514, No. 12237-12237, No. 42
−26345, U.S. Patent No. 2525753, U.S. Patent No. 2594293
No. 2641928, No. 2763639, No. 2763639, No.
No. 3118766, No. 3132945, No. 3186846, No.
3312553, British Patent Nos. 861414, 1033189, etc.), proteins such as albumin and casein, cellulose compounds such as carboxymethyl cellulose and hydroxyethyl cellulose, agar, natural polymers such as sodium alginate, polyvinyl alcohol , poly-N-vinylpyrrolidone, polyacrylic acid copolymer, polyacrylamide or derivatives thereof, and synthetic hydrophilic binders such as partial hydrolysates.
These hydrophilic binders can be used alone or in combination. These hydrophilic binders are also advantageously used to form non-photosensitive layers such as antihalation layers, interlayers, protective layers (or release layers), back layers or image-receiving layers. The binder in the silver halide emulsion layer has a weight ratio of 0.3 to silver halide converted to silver acetate.
5, preferably in the range of 0.5 to 3. The silver halide may be any one of silver chloride, silver bromide, silver chlorobromide, or a combination thereof with silver iodide. Emulsions containing silver chloride as a main component are considered preferable for image reproduction in terms of both chemical development speed and dissolution speed. It is preferable to use a silver chloride, silver chlorobromide, silver chloroiodide, or silver chloroiodobromide emulsion containing 90 mol % or more of chloride. Silver halide emulsions can also be spectrally sensitized in blue, green, and red. It can be a merocyanine, cyanine dye or other sensitizing dye. Furthermore, the silver halide emulsion can be chemically sensitized with various sensitizers. For example, sulfur sensitizers (e.g. hypo, thiourea, gelatin containing labile sulfur, etc.), noble metal sensitizers (e.g. gold chloride, gold rhodan, ammonium chloroplatinate, silver nitrate, silver chloride, palladium salts, rhodium salts, iridium salt,
rutinium salts, etc.), polyalkylene polyamine compounds described in US Pat. No. 2,518,698, etc., iminoamino-methanesulfinic acid described in German Patent No. 1,020,864, and reduction sensitizers (e.g., stannous chloride, etc.) are advantageously used. . The back layer desirably provided on the back side of the support contains a hydrophilic colloid in an amount necessary to maintain curl balance with the photosensitive layer side. The amount depends on the total amount of hydrophilic colloid on the photosensitive layer side, the amount of white inorganic pigment, etc. The constituent elements of the diffusion transfer material according to the present invention may further contain various additives. For example, formalin, mucochromic acid, chromium alum, vinyl sulfone compounds, epoxy compounds,
Hardeners such as ethyleneimine compounds, mercapto compounds, anti-capri agents or stabilizers such as tetraazaindene, saponins as surfactants, sodium alkylbenzene sulfonates, sulfosuccinic acid ester salts, alkylaryls described in US Pat. No. 2,600,831. Anionic compounds such as sulfonates and amphoteric compounds as described in US Pat. No. 3,133,816, as well as waxes, polyol compounds, wetting agents such as glycerides of higher fatty acids or higher alcohol esters, N-guanylhydrazone compounds, Mordants such as quaternary onium compounds and tertiary amine compounds, diacetyl cellulose, styrene-perfluoroalkylene sodium maleate copolymer, alkali reaction product of styrene-maleic anhydride copolymer and P-aminobenzenesulfonic acid Antistatic agents such as salts, matting agents such as polymethacrylic esters, polystyrene, colloidal silicon oxide, acrylic esters,
Film property improvers such as various latexes, styrene-maleic acid copolymers, thickeners such as those disclosed in Japanese Patent Publication No. 36-21574, antioxidants, developing agents, pH adjusters, etc. can be used. A plurality of hydrophilic colloid layers can be applied in several parts, or can be applied in multiple layers simultaneously. The coating method may be any known method and is not limited. After the treatment used in the diffusion transfer method, alkaline substances such as sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium triphosphate, silver halide solvents such as sodium thiosulfate, ammonium thiothianate, cyclic imide compounds, thiosulfate, etc. Preservatives such as salicylic acid, such as sodium sulfite, thickening agents such as hydroxyethyl cellulose, carboxymethyl cellulose, antifoggants such as potassium bromide, 1-phenyl-5-mercaptotetrazole, etc., developer modifiers such as polyoxy Alkylene compounds, onium compounds, developing agents such as hydroquinone, 1-phenyl-
3-pyrazolidone and the like, carkanolamine and the like can be included. However, in a highly alkaline processing solution containing this developing agent, the developing agent suffers from air oxidation and loses its effectiveness.
That is, this drawback can be largely avoided by incorporating it into the silver halide emulsion layer and/or the hydrophilic colloid layer which has a water-permeable relationship therewith. In diffusion transfer materials containing such a developing agent, an alkaline active liquid containing no or substantially no developing agent is usually used. The DTR method using an alkaline activated liquid was developed in
-27568, Sho 47-30856, Sho 51-43778, etc. can be referred to. The present invention will be explained below using examples. Example 1 An aqueous solution of inert gelatin containing 2% bromide was prepared by simultaneously adding an aqueous solution of sodium chloride and potassium bromide and an aqueous silver nitrate solution at a rate of 4 ml/min while stirring vigorously while maintaining the aqueous solution of inert gelatin at 60°C. ,
Three types of silver chlorobromide monodisperse emulsions were prepared. These emulsion grains have average grain sizes of 0.3, 0.45, and 0.65 μ, cubic crystal habit, and 90% of the total grain size for all three types.
More than % by weight were within ±40% of the average particle size. After these emulsions were precipitated, washed with water and redissolved, they were subjected to sulfur sensitization and gold sensitization using sodium thiosulfate and potassium chloroaurate. The emulsion thus prepared was orthosensitized by adding a sensitizing dye, and made up by adding a surfactant and a hardening agent. A 110 g/ ^m2 paper support coated on both sides with polyethylene was coated with 0.3 g/m2 on one side to prevent halation.
g/m ² carbon black, 1.0 g/m ² hydroquinone and 0.2 g/m ² 1-phenyl-4.4
- Gelatin 4 containing dimethyl-3-pyrazolidone
A subbing layer of 1.5 g/m ² of gelatin is applied above which an emulsion layer (gelatin 1.5 g/m ² ) having three average grain sizes according to Table 1 is applied. Both the undercoat layer and emulsion layer are adjusted to pH=4.0. A gelatin layer necessary for curl control is provided on the back side of the support, and the pH of this layer is set to 4.5.

[Table] Using these samples, we used a thin line original with a line width of 10μ to 100μ and used a reflective wedge to check how many micrometers of fine line could be reproduced while adjusting the degree of printing. In other words, a fine-line manuscript is sent to a Dainippon Screen plate-making camera,
It was photographed with an ARTGRAPHICA 601 camera, brought into close contact with the image-receiving material, passed through a normal flosser containing the following diffusion transfer processing solution, and peeled off after 60 seconds. The treatment temperature was 30°C. Processing liquid water for diffusion transfer 800ml Anhydrous sodium sulfite 40g Sodium phosphate (12H ₂ O) 75g Potassium hydroxide 5g Sodium thiosulfate (5H ₂ O) 20g Potassium bromide 1g 1-phenyl-5-mercapto-tetrazole
0.1g The total amount is made up to 1 with water.As is clear from Table 1, 2 of the present invention
(0.45μ) can reproduce a thin line of 20μ, but comparative examples 1 (0.3μ) and 3 (0.65μ) both have a value of 30μ, indicating that the light-sensitive material for diffusion transfer of the present invention has excellent image reproducibility. . Example 2 For comparison, using the single jet method, the average particle size was 0.45μ, but
A silver chlorobromide emulsion (2 mole % bromide) was prepared in which 20% by weight of the total grains were not within ±40% of the average grain size. A coating sample was prepared using this emulsion in the same manner as in Example 1. (Samples 4, 6, 8)
Using the 0.45μ silver chlorobromide monodispersed emulsion of Example 1,
For both, samples with various amounts of silver were prepared according to Table 2. When the same treatment as in Example 1 was carried out at two treatment temperatures, 23°C and 30°C, the results shown in Table 2 were obtained.

[Table] Emulsions that are not monodisperse are highly dependent on silver content;
At silver amounts of 1.0 and 0.6 g/m ² , the image reproducibility is inferior to that of the monodisperse emulsion of the present invention. In particular, it can be seen that in processing at 30°C, emulsions that are not monodisperse are easily affected by the amount of silver, and in the case of silver amounts of 1.0 and 0.6 g/m ² , they are easily affected by the processing temperature. Therefore, the monodisperse emulsion of the present invention has excellent image reproducibility and provides favorable results, particularly in the case of low silver. Furthermore, it is less dependent on processing conditions and has excellent image reproducibility during high-temperature processing. Example 3 Although Examples 1 and 2 were evaluations of positive ruled lines, this example also evaluated negative ruled lines. In the same manner as in Example 1, the average particle size was
A silver chloride monodisperse emulsion having a particle size of 0.55 μm was prepared, and samples with various amounts of silver were prepared according to Table 3. These samples were evaluated for image reproducibility in the same manner as in Example 1 using thin line originals having positive ruled lines and negative ruled lines, and the results shown in Table 3 were obtained.

[Table] As the amount of silver decreases, positive ruled lines become more difficult to reproduce, but negative ruled lines become easier to reproduce. If you look at it, image reproducibility does not deteriorate due to the reduction in silver.
However, in terms of the ease with which positive ruled lines can be reproduced,
The impact of low silver prices is significant.

Claims (1)

[Claims] 1. The average grain size of the silver halide emulsion grains containing 90 mol% or more of silver chloride is in the range of 0.38μ or more and 0.6μ or less, and 90% by weight or more of all grains have an average grain size. A light-sensitive material for diffusion transfer that has a silver halide emulsion layer containing within ±40% of 2. The light-sensitive material for diffusion transfer according to claim 1, which has an antihalation layer containing a black pigment and/or a white pigment on a support. 3 Claim 1 containing an amount of silver (Ag conversion value) equivalent to 0.45 g/m ² or more and 1.1 g/m ² or less
The light-sensitive material for diffusion transfer according to item 1 or 2.